Node.js Errors

This error occurs when node-gyp fails to configure the build environment for native Node.js addons. It typically happens due to missing build tools, incompatible Python versions, or missing Visual Studio components on Windows.

This TypeError occurs when path.relative() is called with non-string arguments, such as undefined, null, numbers, or objects. Both the from and to parameters must be valid string values representing file paths.

The FORMERR error occurs when a DNS server rejects a Node.js DNS query as malformed. This typically happens due to incompatible DNS extensions, invalid hostnames, or DNS server configuration issues.

The ENOTFOUND error occurs when Node.js cannot resolve a hostname to an IP address through DNS lookup. This typically happens with invalid hostnames, typos in URLs, network connectivity issues, or DNS configuration problems.

DNS timeout errors occur when Node.js cannot resolve a hostname within the expected timeframe, often due to network issues, slow DNS servers, or threadpool exhaustion. This guide shows how to configure timeouts and implement caching strategies.

This error occurs when you attempt to send data on an HTTP/2 stream that has already been closed or ended. The stream closure can happen due to receiving a remote reset, the stream ending normally, or attempting operations after the stream has been destroyed. This commonly occurs with HTTP/2 connections when proper stream lifecycle management is not followed.

This warning appears when code uses the deprecated util.pump() function for piping streams. Node.js deprecated this function in favor of the more robust stream.pipe() method and the modern stream.pipeline() function, which provide better error handling and automatic cleanup.

This error occurs when a readable stream is closed or destroyed before all data has been consumed. It typically happens when the underlying resource terminates unexpectedly, when network connections are interrupted, or when stream lifecycle events are not properly synchronized.

This error occurs when Node.js encounters ES6 import syntax in a file that is being treated as a CommonJS module. Node.js defaults to CommonJS and requires explicit configuration to use ES modules with import/export syntax.

This error occurs when Node.js attempts an HTTPS connection to a server whose SSL/TLS certificate does not include the hostname or IP address being used in the request. Node.js validates that the connection target matches the Subject Alternative Names (SANs) in the certificate for security.

The HPE_UNEXPECTED_EOF error occurs when Node.js HTTP parser encounters an unexpected end-of-file during HTTP response parsing. This typically happens when the server closes the connection prematurely before sending the complete HTTP response, leaving the client with incomplete data.

This error occurs when Node.js zlib compression fails during the deflate operation. It typically indicates corrupted input data, memory allocation issues, or mismatched compression parameters.

This error occurs when attempting to kill a process that no longer exists or never existed. The ESRCH code indicates that the specified process ID (PID) cannot be found in the system.

This error occurs when native Node.js modules are compiled for one Node.js version but run with a different version. The version numbers (e.g., 93 vs 94) represent the NODE_MODULE_VERSION ABI used by different Node.js releases.

Node.js cannot find the entry point specified in package.json because the 'main' field is either missing or points to a file that doesn't exist. This prevents the module from being loaded when imported or required.

This error occurs when a package requires a peer dependency that is not installed in your project. Starting with npm 7, peer dependencies must be installed manually, and npm will fail the installation if they are missing.

This warning occurs when a Promise rejection is initially left unhandled, triggering Node.js to track it, and then a catch handler is attached later in a subsequent event loop tick.

This error occurs when Node.js crypto module cannot parse a public key because it is in an incorrect format, has encoding issues, or lacks proper structure. The crypto.createPublicKey() function expects keys in specific formats like PEM or DER with correct headers and encoding.

This issue occurs when multiple asynchronous operations execute concurrently and complete in an order different from what the code expects, leading to incorrect state, stale data, or data corruption. While Node.js is single-threaded, its asynchronous nature means operations can finish in any order.

This error occurs when implementing a timeout pattern with Promise.race() where the racing promise never resolves or rejects within the specified timeout period. The timeout promise wins the race, but the original promise remains pending indefinitely.

This error occurs when Node.js attempts a TCP connection but the operating system cannot find a route to the destination host or network. It indicates network configuration issues, routing problems, or firewall restrictions blocking access to the target host.

This error occurs when Node.js cannot access sufficient system entropy to generate cryptographically secure random bytes. It typically happens on systems with depleted entropy pools, especially right after boot, in containerized environments, or on systems with limited hardware entropy sources.

This error occurs when JavaScript code attempts to access a variable that hasn't been declared, is out of scope, or was misspelled. It's one of the most common errors in Node.js and typically indicates an undeclared variable reference.

HTTP requests fail when they exceed the configured timeout threshold, typically defaulting to 30 seconds. This occurs when the remote server is slow to respond, network connections are unstable, or response payloads are too large to process within the timeout window.

This error occurs when Node.js attempts to import a directory but cannot locate an index.js file or a valid entry point specified in package.json. It typically happens when directory imports rely on implicit index file resolution.

This error occurs when a module attempts to import or require its own filename or path, creating an unintended self-reference. Node.js cannot resolve the module because the import points back to the same file, preventing proper module loading and initialization.

This error occurs when Node.js cannot initialize a TLS/SSL connection due to invalid certificate, key, or OpenSSL configuration issues. Common causes include incompatible certificate formats, missing key files, unsupported cipher suites, or OpenSSL version mismatches.

This error occurs when path.resolve() is called without any arguments in certain contexts or configurations. While path.resolve() with no arguments typically returns the current working directory, this specific error suggests stricter validation or a null/undefined value being passed instead of truly empty arguments.

This error occurs when the JavaScript parser encounters a token it does not recognize at the given position. It typically indicates missing brackets, quotes, semicolons, invalid characters, or syntax violations that prevent the code from being parsed correctly.

This error occurs when Node.js tries to establish a TLS connection using a protocol version that the server doesn't support. TLS 1.0 and 1.1 are disabled by default in modern Node.js versions; ensure both client and server use TLS 1.2 or higher.

This error occurs when Node.js cannot parse a URL string using the WHATWG URL standard. The URL constructor is strict and rejects malformed URLs, missing protocols, unencoded special characters, or incomplete URL structures. This is a common issue when building dynamic URLs or handling user input.

This error occurs when a Buffer is converted to a string using an encoding that differs from the original encoding used to create the Buffer. Node.js supports specific encodings (utf8, hex, base64, etc.), and mismatches produce garbled output or replacement characters.

This error occurs when attempting to create a Buffer or typed array larger than the platform maximum (typically 2GB on 32-bit systems, 4GB on 64-bit). The allocation fails because V8 cannot handle arrays larger than what a Small Integer can represent.

This error occurs when attempting to perform operations on a Node.js stream that has already been explicitly destroyed or closed. Once destroyed, a stream cannot be reused and must be recreated.

This error occurs when a function calls itself recursively without a proper base case or termination condition, exhausting the call stack. Stack overflow can also happen during deep object operations, circular event listeners, or when processing deeply nested data structures.

This error occurs when a server is temporarily unable to handle requests, typically due to being overloaded, down for maintenance, or having unavailable dependencies. In Node.js, you may receive 503 from external APIs or return 503 when your own application cannot accept traffic. This guide covers both scenarios.

This error occurs when attempting to write data to a Node.js stream that has been closed, ended, or destroyed. Common causes include writing after calling end(), writing to destroyed streams, or writing to inherently read-only streams.

This error occurs when an exception is thrown inside a callback function and not properly caught. Since callbacks execute asynchronously, exceptions thrown within them cannot be caught by surrounding try-catch blocks, causing the error to propagate and potentially crash your application.

SSL protocol errors occur when Node.js cannot verify an HTTPS server's certificate. This happens due to missing intermediate certificates, self-signed certificates, expired certificates, or incorrect system time. Learn how to diagnose and fix certificate verification failures safely.

This error occurs when a callback function doesn't follow Node.js's error-first callback convention, which requires the first parameter to be reserved for an error object. Node.js expects callbacks to accept an error as the first argument (null if no error), followed by result data.

This error occurs when attempting to read data from a Node.js stream that is not in a readable state, has already been consumed, or was never properly initialized as readable.

This error occurs when an asynchronous operation in Node.js is deliberately cancelled using AbortController or times out. It indicates that the operation was terminated before completion, either programmatically or due to exceeding a time limit.

This error occurs when Node.js child_process.spawn() cannot locate or execute the specified command or binary. ENOENT ('Error: No such file or directory') typically means the executable is missing, not installed, misspelled, or not in the system PATH. This frequently happens when trying to run external commands, system binaries, or globally installed packages from within Node.js.

This error occurs when Node.js attempts to resolve a symbolic link to its actual target using fs.realpath() or fs.realpathSync(), but the symlink points to a non-existent file or directory. This typically indicates a broken symlink in your project.

This error occurs when Node.js attempts to start an HTTPS server using an encrypted private key file without providing the passphrase needed to decrypt it. The server startup fails because the key cannot be decrypted and used for SSL/TLS operations.

This error occurs when node-gyp cannot find a C++ compiler on your system. node-gyp is a tool used by Node.js packages to compile native C++ modules. It requires a C++ compiler (like g++ on Linux, clang on macOS, or Visual Studio on Windows) to be installed and properly configured.

This error occurs when node-gyp cannot locate a Python executable to compile native Node.js addons. Python is a required dependency for node-gyp to build C++ modules during npm package installation.

This error occurs when npm lifecycle scripts (preinstall, postinstall, prepublish, etc.) fail during package installation. These scripts are defined in package.json and run at specific stages of the installation process. Failures typically stem from missing build tools, permission issues, or incompatible dependencies.

This error occurs when node-gyp attempts to compile native Node.js modules on Windows but cannot locate VCBuild.exe, a component of Visual Studio C++ build tools. It typically happens during npm install when packages require native compilation.

This error occurs when Node.js cannot write a heap snapshot file using v8.writeHeapSnapshot(). It typically indicates insufficient disk space, lack of write permissions in the target directory, or insufficient memory to complete the snapshot operation.

The ELIFECYCLE error occurs when an npm script defined in package.json fails during execution and exits with a non-zero status code. This is a wrapper error that indicates the underlying script command encountered a problem.

This error occurs when your Node.js application exceeds the operating system's limit on the number of file descriptors that can be opened simultaneously. File watchers like fs.watch() are particularly affected, especially in development environments using tools like Webpack, Jest, or file watching services.

This error occurs when attempting to set HTTP headers with invalid characters, such as control characters, newlines, or improperly encoded non-ASCII text. Node.js enforces strict HTTP header validation to prevent security vulnerabilities.

This error occurs when you try to run an npm script that is not defined in the scripts section of your package.json file. npm cannot execute a script it cannot find.

This error occurs when you pass an invalid entry type to PerformanceObserver.observe() in Node.js's perf_hooks module. The observer only accepts specific, predefined entry types.

This TypeError occurs when you pass a non-string value to path.parse(), most commonly undefined, null, or a Buffer. The path module's parse() method strictly requires a string argument to extract path components.

The setgid EPERM error occurs when a Node.js process attempts to change its group ID without sufficient privileges. This commonly happens when setuid() is called before setgid(), or when the process lacks CAP_SETGID capability.

This error occurs when an application or package requires a specific Node.js version, but a different version is currently running. Common in projects with strict version requirements or when switching between projects with different Node.js dependencies.

This error occurs when implementing a custom writable stream without properly defining the required _write() method. Node.js expects all custom writable streams to implement this internal method to handle data processing.

This error occurs when passing a non-string value as the separator parameter to querystring.parse() or querystring.stringify(). The querystring module requires separator and assignment parameters to be strings, not null, undefined, numbers, or other types.

This error occurs when creating a custom Readable stream class without implementing the required _read() method. Node.js expects all custom Readable streams to define how data is generated and pushed to consumers.

This error occurs when a Node.js client attempts to connect to a server using incompatible TLS/SSL protocol versions. The TLS handshake fails because the client and server cannot agree on a mutually supported protocol version.

This error occurs when Node.js cannot find any valid cipher suites for establishing a TLS/SSL connection, typically due to invalid cipher configuration, security level conflicts, or incompatible cipher specifications.

This error occurs when a TLS client attempts to use session resumption via session tickets, but the server has explicitly disabled this feature through the SSL_OP_NO_TICKET flag. Session tickets are a performance optimization that allows clients to resume previous TLS sessions without a full handshake.

The Z_DATA_ERROR occurs when Node.js zlib detects corrupted or invalid compressed data during decompression. This typically happens when attempting to decompress data with incorrect headers, truncated content, or using the wrong decompression method.

This error occurs when attempting to verify a JSON Web Token (JWT) that has passed its expiration time. The jsonwebtoken library throws a TokenExpiredError when the token's exp claim indicates it is no longer valid.

This error occurs when an HTTP client follows too many redirect responses, exceeding the configured limit. It commonly happens with axios, node-fetch, or the follow-redirects package when a server creates a redirect loop or when legitimate redirects exceed the maxRedirects threshold (default 21).

This error occurs when Node.js cannot load a compiled native addon module from the expected build directory. Native modules are C++ extensions that must be compiled for your specific platform and Node.js version.

Node.js throws a ModuleNotFoundError when it cannot locate a required module in the node_modules directory or module resolution paths. This typically happens when a package is not installed or the import path is incorrect.

This error occurs when attempting to use require() to import an ES module in a CommonJS context. Node.js enforces strict module system boundaries, and ES modules must be imported using import statements or dynamic import().

This error occurs when attempting to use __dirname or __filename in ES modules. These CommonJS globals are not available in ES module scope, requiring alternative approaches using import.meta.url or the newer import.meta.dirname.

This error occurs when a cryptographic key derivation operation fails in Node.js, typically affecting password hashing functions like pbkdf2, scrypt, or bcrypt. The failure usually stems from invalid parameters, resource constraints, or missing native module support.

npm displays a warning when an optional dependency cannot be installed due to platform incompatibility or build failures. This is informational and does not prevent your project from working.

This error occurs when a PassThrough stream is used before proper initialization or when extending the PassThrough class without calling the parent constructor correctly.

This error occurs when Node.js attempts to read a certificate or private key file that is not properly formatted in PEM format. The OpenSSL library cannot find the required PEM header markers or the file structure is malformed.

This error occurs when the jsonwebtoken library fails to parse or decode a JWT token during verification. The token structure is malformed, corrupted, or contains invalid encoding that prevents successful parsing.

This error occurs when a Node.js stream attempts to write data to a pipe whose read end has been closed. It typically happens when a client disconnects mid-response or when a stream is closed unexpectedly during data transfer.

This error occurs when a Node.js Transform stream's _transform() method fails to call its callback function, or when the stream callback is invoked without data being pushed to the output buffer. It causes the stream to hang indefinitely, stopping all further data processing through the pipeline.

This warning appears when code uses the deprecated Buffer() constructor instead of the modern Buffer.alloc(), Buffer.allocUnsafe(), or Buffer.from() methods. Node.js deprecated this constructor because it can inadvertently introduce security vulnerabilities by allocating uninitialized memory.

This error occurs when verifying an ECDSA (Elliptic Curve Digital Signature Algorithm) signature fails, indicating the signature does not match the expected value for the given data and public key. Common causes include mismatched elliptic curves, incorrect signature encoding formats, or data corruption during transmission.

This error occurs when fs.mkdir() attempts to create a directory that already exists. It commonly happens in concurrent operations, race conditions, or when running build scripts multiple times without proper existence checks.

This error occurs when Node.js attempts to perform I/O operations on a file descriptor that has already been closed or is invalid. It commonly happens with double-close scenarios, premature stream closures, or attempting to read/write after a file handle has been released.

This error occurs when the Node.js cluster module attempts to create a worker with an ID that already exists in the active worker pool. It typically happens when worker IDs are manually assigned or when the primary process tries to create duplicate workers without properly tracking existing worker IDs.

This error occurs when Node.js attempts to establish a TCP connection to a server (database, API, or service) but the connection is actively refused. The target server is either not running, not listening on the specified port, or actively rejecting connections due to firewall rules or network configuration.

This error occurs when Node.js crypto functions receive a private key in an incompatible or malformed format. The crypto module expects keys in specific encodings (PEM, DER, or JWK) with proper structure and headers.

This error occurs when a callback function passed to process.nextTick() throws an uncaught exception. Since nextTick callbacks execute before the event loop continues, unhandled errors in these callbacks will crash the Node.js process.

This error occurs when a Promise remains in a pending state indefinitely because neither resolve() nor reject() is ever called. The code after await never executes, causing operations to hang or the application to appear frozen.

Promise.all() rejects immediately when any single promise in the array rejects, causing an unhandled promise rejection if not properly caught. The entire operation fails even if other promises would have succeeded.

This warning occurs when promises remain unresolved indefinitely, preventing JavaScript's garbage collector from freeing memory. Long-lived or infinite promise chains accumulate in memory, eventually leading to performance degradation or out-of-memory crashes.

This error occurs when your Node.js application or npm tries to connect through a proxy server that requires authentication credentials. The request is rejected because no valid username and password were provided to the proxy.

This error occurs when code attempts to use a non-function value as a function, or when a function is expected to return a promise but returns a non-thenable value instead. It commonly happens in promise chains, async/await operations, or when working with promise constructors.

Node.js throws this error when require() or import attempts to load a module from a directory path that does not exist in the filesystem. This commonly happens due to incorrect paths, missing installations, or misconfigured module resolution.

A segmentation fault occurs when Node.js or a native addon attempts to access memory it is not permitted to access, causing the process to crash with a "Segmentation fault (core dumped)" message. This typically indicates a bug in native C/C++ modules rather than JavaScript code.

The spawn EACCES error occurs when Node.js attempts to spawn a child process but lacks execute permissions on the target executable. This commonly happens with binary files in node_modules or custom scripts that are missing the executable bit.

Your setImmediate() callback threw an unhandled exception or failed during execution. This error occurs because exceptions in setImmediate callbacks cannot be caught with try-catch and propagate unchecked through the Node.js event loop, crashing your process.

This error occurs when Node.js cannot verify the SSL/TLS certificate of a server you are trying to connect to. It typically happens with self-signed certificates, expired certificates, or missing intermediate certificates. The fix depends on whether you are in a development environment or production.

Node.js StringDecoder throws an error when you pass an unsupported or misspelled encoding. This happens when working with streams or buffers with invalid encoding specifications.

This error occurs when Node.js receives a malformed or unrecognized timezone string from the TZ environment variable. The TZ variable expects valid IANA timezone identifiers (like "America/New_York" or "Europe/London") or POSIX timezone strings, but receives an invalid or misspelled value instead. This causes date and time operations to fail or behave unpredictably.

A TLS handshake timeout occurs when the client and server fail to complete the SSL/TLS negotiation within the timeout period (default 120 seconds). This typically indicates network delays, server resource constraints, or infrastructure issues.

This error occurs when the hostname sent during TLS handshake (Server Name Indication) does not match the hostname on the SSL/TLS certificate. The server receives a different SNI name than what the certificate is valid for, causing verification to fail.

This error occurs when attempting to call cluster.fork() from a worker process instead of the primary (master) process. The cluster module enforces a strict master-worker hierarchy where only the primary process can spawn new workers.

This error occurs when Node.js receives an HTTP response with malformed chunked transfer encoding. The HTTP parser cannot properly decode the response body because the chunk format violates HTTP/1.1 specifications.

This error occurs when an exception is thrown inside a deferred callback (setTimeout, setImmediate, or process.nextTick) without proper error handling, potentially crashing the Node.js process.

The EAGAIN error indicates that a requested I/O operation cannot be completed immediately because the resource is temporarily unavailable. This is a recoverable error that signals Node.js to retry the operation later rather than failing permanently.

This error occurs when a TCP connection is forcibly closed by the remote server or peer before the operation completes. It typically happens during HTTP requests when the server closes the connection unexpectedly, often due to timeout mismatches, keep-alive issues, or network problems.

This error occurs when a file or directory name exceeds the maximum length allowed by the operating system's filesystem. Most filesystems limit individual filename components to 255 bytes, and Node.js throws ENAMETOOLONG when attempting filesystem operations with paths that exceed this limit.

Occurs when using require() or import with relative paths (./ or ../) to modules that don't exist or have incorrect paths.

This error occurs when you pass an invalid depth value to Node.js util.inspect() function. The depth parameter must be a non-negative integer (0 or greater), null, or Infinity—passing a negative number triggers this RangeError.

This error occurs when a Promise is rejected without passing an error object or reason. Instead of a meaningful error message, Node.js displays "undefined", making debugging extremely difficult.

Occurs when attempting to create or manipulate a string that exceeds JavaScript's maximum string length limit of approximately 1GB (2^29 - 24 bytes in V8).

This error occurs when Node.js encounters a protocol-level communication failure, most commonly during HTTPS requests. It typically indicates SSL/TLS handshake issues, protocol mismatches, or connection interruptions between client and server.

This error occurs when Node.js cannot resolve a hostname to an IP address through DNS lookup. It commonly happens with network requests using fetch, axios, or http when the domain name is misspelled, the DNS server is unreachable, or the hostname does not exist.

This error occurs when Node.js cannot resolve a hostname to an IP address through DNS. It typically happens when making HTTP requests to domains that don't exist, are misspelled, or when DNS resolution fails due to network connectivity issues.

This error occurs when a Node.js application attempts to write to a file or directory on a read-only filesystem. Common in containerized environments, serverless platforms, and systems with intentionally read-only root filesystems.

This error occurs when importing from an ES module that doesn't export the requested name. It commonly happens when trying to use a default import on a module that only has named exports, or when mixing ESM and CommonJS module systems.

This warning appears when more than 10 event listeners are attached to a single EventEmitter instance, indicating a potential memory leak from listeners not being properly cleaned up.

This error occurs when an asynchronous operation exceeds its configured time limit without completing. Common in network requests, database queries, and long-running async operations.

This error occurs when a network request does not complete within the specified time limit and the socket connection times out. It commonly happens with HTTP clients when the server takes too long to respond or network connectivity issues prevent timely communication.

This error occurs when you try to access a property or function from a module that was not properly exported, or when module.exports is assigned inside a callback. It commonly happens when mixing CommonJS and ES Module syntax or importing non-existent named exports.

This error occurs when attempting to access a property on a variable that is undefined or null. It is one of the most common runtime errors in Node.js and JavaScript, typically caused by accessing data before it is initialized or when API responses are missing expected fields.

This error occurs when you try to start a Node.js server on a port that is already occupied by another process. The system refuses to bind to the port because another application is already listening on it.

This error occurs when a TCP connection is forcibly closed by the remote server or network device before your Node.js application finishes reading data. The connection is abruptly terminated by sending a TCP RST packet instead of a graceful close.

This error occurs when the crypto.createHmac() method receives a key argument that is not a valid type. Node.js requires the HMAC key to be a string, Buffer, TypedArray, DataView, or KeyObject, and passing undefined, null, or other invalid types will cause this error.

This system-level error occurs when attempting to initiate a network operation (like a socket connection) that is already in progress. It commonly happens when reconnecting sockets too quickly or trying to bind resources that are already being accessed.

This error occurs when Node.js attempts to establish a TCP connection but the operating system cannot find a network route to the destination. The connection fails because no routing path exists between your system and the target host.

This error occurs when you attempt to call a value as a function, but that value is not actually a function. It commonly happens due to typos in function names, calling properties that hold non-function values, or issues with module loading and scope.

This Node.js error occurs when the operating system blocks a file system operation due to insufficient permissions, file locking by another process, or security restrictions. Common scenarios include writing to protected directories, accessing files opened by other applications, or operating on files locked by antivirus software.

This error occurs when Node.js file system operations attempt to read, write, or manipulate a directory as if it were a regular file. The operation expects a file path but receives a directory path instead.

This error occurs when using latin1 (ISO-8859-1) encoding in Node.js Buffer operations on versions that don't support it. The fix is to either upgrade Node.js to v6.4.0 or later, or use an alternative encoding method.

Node.js throws ERR_UNKNOWN_FILE_EXTENSION when trying to import or execute files with unrecognized extensions. This commonly occurs with TypeScript files (.ts), Python files (.py), or other non-JavaScript file types that Node.js cannot natively process.

This fatal error occurs when a Node.js process attempts to allocate more memory than the available heap size allows. The process crashes because it cannot continue execution without the requested memory allocation.

The ENODEV error occurs when Node.js attempts to read from a device that doesn't exist or is unavailable. This commonly happens with hardware devices like Bluetooth adapters, TTY devices, or when performing device-specific operations on unsupported file descriptors.

This error occurs when Node.js attempts to write data to a stream, pipe, or socket that has already been closed by the receiving end. It's a POSIX error indicating the connection was terminated before all data could be transmitted.

This error occurs when Node.js receives HTTP response headers that contain invalid characters or do not comply with strict HTTP/1.1 standards. Node.js v12+ uses a stricter HTTP parser that rejects malformed headers that browsers might accept.

This error occurs when attempting to allocate a buffer that exceeds Node.js maximum buffer size limits. On 32-bit systems the limit is ~1GB, while 64-bit systems allow up to ~2GB.

This error occurs when you attempt to set an HTTP header with a value containing characters that violate HTTP header specifications. Node.js strictly validates header values to prevent header injection attacks and protocol violations.

This error occurs when the Inter-Process Communication (IPC) channel between a parent and child process created with child_process.fork() fails or closes unexpectedly, preventing message passing between processes.

This error occurs when Node.js runs out of memory while executing your application. By default, Node.js limits heap memory to approximately 1.5GB on 64-bit systems, which may be insufficient for memory-intensive operations like processing large files or building complex applications.

This error occurs when you call server.listen() more than once on the same server instance. Once a server is listening on a port, you cannot call listen() again without closing it first, as the port binding is already established.

This error occurs when Node.js detects conflicting or invalid HTTP trailer headers in a chunked transfer encoding response. Trailers can only be used with chunked encoding, but certain conditions prevent their proper use or declaration.

This error occurs when your Node.js application attempts to write data to a network socket that has already been destroyed or closed. The socket is no longer available for communication and cannot accept new data.

This error occurs when Node.js fails to compile native C/C++ addons during package installation. It indicates a problem with the compilation environment, missing build tools, or incompatible dependencies required by node-gyp.

This error occurs when attempting to use HTTP trailer headers incorrectly with chunked transfer encoding. Trailer headers can only be sent after the message body when chunked encoding is properly enabled and the Trailer header is declared upfront.

This error occurs when Node.js detects corrupted or invalid V8 code cache data. The V8 engine uses code caching to speed up script compilation, but when the cached data becomes corrupted or incompatible, validation fails and Node.js must recompile the affected modules.

This error occurs when a Node.js worker thread exits unexpectedly due to an unhandled exception, memory limit, or forced termination. The main thread loses communication with the worker, leaving operations incomplete.

Occurs when attempting to use CommonJS require() to import an ES module, which only supports import statements.

Occurs when Node.js cannot resolve a module path from the project root, typically due to incorrect package.json configuration, missing dependencies, or path resolution issues.

Occurs when Node.js attempts to perform I/O operations on a file descriptor that is closed, invalid, or doesn't exist.

Occurs when Node.js cannot find an npm package that should be installed in node_modules, typically due to missing installation or corrupted node_modules.

Occurs when Node.js cannot establish a TCP connection to MySQL server because the server is not running, not listening on the specified port, or blocked by firewall.

Occurs when Node.js application attempts to open more MySQL connections than allowed by the max_connections server setting.

This error occurs when attempting to write data to a writable stream after it has been closed with end() or destroy(). Once a stream is ended, it cannot accept any additional data.

This error occurs when attempting to use the worker_threads module in a Node.js environment where worker threads are unavailable, either due to an outdated version, custom build configuration, or missing experimental flags in older versions.

This error occurs when jwt.verify() receives an invalid or improperly formatted JSON Web Token. A valid JWT must have exactly three base64url-encoded parts separated by periods (header.payload.signature).

This fatal error occurs when Node.js runs out of memory trying to allocate space in the JavaScript heap. It typically happens when processing large datasets, running memory-intensive operations, or when there are memory leaks that gradually consume all available heap space.

This error occurs when an exception is thrown inside a setTimeout callback function. Since the callback executes asynchronously, the error cannot be caught by outer try-catch blocks and will crash your application unless properly handled.

This error occurs when a write operation to a Node.js stream takes longer than the configured timeout threshold. It typically happens when downstream consumers are slow or unresponsive, causing backpressure to accumulate and the write operation to stall.

This error occurs when your Node.js server receives connections faster than it can accept them, causing the TCP backlog queue to overflow. The server cannot handle the rate of incoming connection requests, and the OS refuses further connection attempts.

This error occurs when you call resume() on a stream that is already in the reading state, indicating a mismatch between pause() and resume() calls. It typically happens with improper backpressure handling or calling resume() multiple times without corresponding pause() calls.

This error occurs when worker processes in a Node.js cluster module are trying to emit 'listening' events but no actual listening server exists in the worker processes. The cluster module expects workers to have a net.Server instance listening on a port to handle incoming connections.

This error occurs when Node.js DNS resolution exhausts all retry attempts after receiving SERVFAIL responses from the DNS server. SERVFAIL indicates the DNS server encountered an error and could not process the query, typically due to zone misconfiguration, DNSSEC validation failures, or temporary server problems.

The DNS NOTFOUND error occurs when a DNS server responds to a query but contains no answer records for the requested domain. This indicates the domain doesn't exist, is improperly configured, or the DNS server lacks the record information. This is different from timeouts or unreachable servers.

This error occurs when you attempt to use an unsupported character encoding with Node.js Buffer operations. Node.js only supports a limited set of standard encodings like utf8, ascii, hex, and base64. Using an invalid encoding name causes a RangeError.

This error occurs when you attempt to read from or write to a Buffer at an offset that is either negative or exceeds the buffer's bounds. Common when using Buffer methods like readUInt8(), write(), slice(), or copy() with invalid offset parameters.

This error occurs when an asynchronous operation takes longer than the specified timeout duration to complete. The promise remains in a pending state past its deadline, triggering a timeout rejection to prevent indefinite waiting.

HTTP 429 Too Many Requests indicates your Node.js application has exceeded the API rate limit. The server is asking your client to slow down request frequency.

This warning occurs when a Promise is rejected but no error handler catches the rejection. Starting from Node.js 15, unhandled promise rejections cause the application to terminate, making proper error handling critical for application stability.

This error occurs when attempting to send a message through a MessagePort that has already been closed or whose worker thread has terminated. The communication channel between the main thread and worker is no longer available.

This error occurs when attempting to access AsyncLocalStorage data outside of an asynchronous context initialized by run() or enterWith(). The store is only available within the callback scope or in operations properly bound to that context.

This error occurs when attempting to decode a base64 string that has incorrect padding. Base64 encoding requires padding to a multiple of 4 characters using the "=" character, and improper padding causes decoding failures in strict validation contexts.

This error occurs when you pass an invalid or unrecognized signal name to Node.js process.kill(). Common causes include using signal numbers instead of names, omitting the SIG prefix, or using platform-specific signals on unsupported systems.

This error occurs when express.json() middleware tries to parse non-JSON content (typically HTML) as JSON. Most commonly caused by requesting a non-existent route that returns a 404 HTML page, or sending malformed JSON to your API.

This error occurs when a Node.js client and server cannot establish a secure TLS/SSL connection during the handshake process. The handshake failure typically stems from protocol version mismatches, incompatible cipher suites, certificate validation issues, or misconfigured TLS settings.

A CORS preflight request failed because the server didn't respond with the required Access-Control-Allow-Origin header. This happens when your Express server doesn't properly configure CORS headers for complex requests (PUT, DELETE, POST with custom headers).

This error occurs when a Node.js application attempts to communicate with a server using an outdated or unsupported protocol version. The server responds with HTTP 426, indicating the client must upgrade to a newer protocol (such as HTTPS, HTTP/2, or a specific TLS version) before the request can be processed.

This error occurs when the URL constructor or URL-related functions receive an argument that is not a string or URL object, such as undefined, null, a number, or other invalid types.

This error occurs when you attempt to register the same Fastify plugin multiple times, either directly in your code or through a chain of dependencies. Fastify prevents duplicate plugin registration to avoid conflicts, state duplication, and unpredictable behavior.

This error occurs when you pass an invalid compression level to Node.js zlib functions like createGzip() or createDeflate(). The compression level must be an integer between -1 (default) and 9 (maximum compression).

This error occurs in Fastify when you attempt to validate request data without providing a schema definition. Fastify requires an explicit schema for request validation, and if missing, it will throw this error. The schema defines the expected structure of request parameters, query strings, bodies, or headers.

This error occurs when using the recursive option with fs.mkdir() or fs.mkdirSync() in an older version of Node.js that does not support this feature. The recursive option was added in Node.js 10.12.0 to create directories recursively with a single command.

This error occurs when Node.js fs.watch() reaches the system limit on file descriptors or inode watchers. The file watching subsystem cannot monitor additional files because the system has exhausted its available watching capacity.

This warning indicates that promises are being continuously created inside setInterval or setTimeout callbacks without proper cleanup, causing memory consumption to grow unbounded. The callback functions and their closures remain referenced, preventing garbage collection.

This error occurs when npm or Node.js cannot locate a package.json file in the directory where you are running commands. The package.json file is required for dependency management and project configuration.

This error occurs when you attempt to set an HTTP response status code to a value outside the valid range of 100-599. The HTTP specification requires status codes to be three-digit numbers within this range.

This error occurs when a client sends a request body that exceeds the server's configured size limit. By default, Express limits request bodies to 100KB, causing this error when larger payloads are sent.

This warning appears when running Node.js with the --pending-deprecation flag or NODE_PENDING_DEPRECATION environment variable. It alerts developers that the Buffer() constructor is scheduled for eventual removal, giving advance notice to update code before the feature becomes fully deprecated.

This RangeError occurs when passing a timeout value that exceeds the maximum 32-bit unsigned integer limit (4,294,967,295 milliseconds, about 49.7 days) to timer functions like setTimeout or setInterval.

A "socket hang up" error occurs when a network connection is unexpectedly closed or terminated before the operation completes. This typically happens during HTTP requests when a server closes the connection without properly finishing the response, or when the socket times out waiting for data.

This error occurs when Node.js attempts an HTTPS connection to a server with an SSL/TLS certificate signed by a Certificate Authority (CA) that is not trusted or recognized. Node.js maintains a list of trusted root CAs, and when a certificate is signed by an unknown or self-signed CA, the connection is rejected.

The remote server rejected the SSL/TLS certificate presented by your Node.js application during the handshake. This occurs when the certificate is invalid, self-signed, or the certificate chain is incomplete.

This error occurs when an asynchronous operation is cancelled using an AbortController before it completes. It commonly happens with fetch requests, file operations, or any API that accepts an AbortSignal when the operation is explicitly aborted or times out.

This error occurs when a test assertion fails using Node.js assert.strictEqual(), indicating that the actual value does not match the expected value using strict equality (===).

A 502 Bad Gateway error occurs when a reverse proxy server (like nginx or a load balancer) receives an invalid or no response from your Node.js application. This typically happens when your app crashes, times out, or fails to respond properly to incoming requests. Fixing this requires identifying why the upstream Node.js server is failing to respond.

This error occurs when data is being written to a Node.js stream faster than it can be consumed, causing the internal buffer to fill up. The stream is experiencing backpressure because the destination cannot drain data quickly enough to keep up with the source.

This error occurs when the await keyword is used outside of an async function context. JavaScript requires await to be inside async functions, async generators, or ES module top-level code to properly handle asynchronous operations.

This error occurs when async operations are being queued faster than they can be processed, causing unbounded memory growth and eventual system failure. It's a classic backpressure problem where producers outpace consumers.

This error occurs when a callback function is invoked more than once in an asynchronous operation, typically when using callback-based flow control libraries like async.js. It is a safety mechanism to prevent unpredictable behavior caused by multiple callback invocations.

This error occurs when attempting to read from or write to a Buffer at an invalid position that exceeds the buffer's allocated memory boundaries.

The maxBuffer exceeded error occurs when a child process produces more output than the buffer can hold. The default buffer size is 1MB, and when stdout or stderr data exceeds this limit, Node.js terminates the child process and throws an error. This commonly happens when executing commands that produce large amounts of output.

This error occurs when Node.js cannot locate a module you are trying to import or require. It typically happens when a package is not installed, the path is incorrect, or dependencies are corrupted.

This error occurs when Node.js attempts to make an HTTPS request but cannot verify the SSL/TLS certificate because it is self-signed or issued by an untrusted Certificate Authority. This is common in corporate networks, development environments, or when connecting to private registries.

This error occurs when a child process spawned by Node.js exits with a non-zero status code, indicating the command or script failed to execute successfully. Exit code 1 typically signals a general error condition in the child process.

This error occurs when an async iterator's next() method returns null instead of a proper iterator result object. Async iterators must return promises that resolve to objects with done and value properties.

This error occurs when attempting to write data to a Node.js net.Socket before the connection is established. The socket must successfully connect to a remote server before any data can be sent. This typically happens when write() is called immediately without waiting for the "connect" event.

This error occurs when a child process spawned by Node.js is terminated by receiving a SIGTERM signal before completing its task. SIGTERM is a termination signal sent by the operating system, container orchestrator, or parent process to request graceful shutdown. Understanding why the process receives SIGTERM and implementing proper signal handling prevents unexpected terminations and data loss.

This RangeError occurs when you try to set an HTTP response status code that falls outside the valid range of 100-599. Node.js strictly validates status codes to ensure compliance with HTTP specifications.

This error occurs when Node.js crypto module attempts to initialize a cipher with an invalid or unsupported algorithm name. The cipher name must match one of the algorithms supported by the OpenSSL library that Node.js is compiled with. Using an incorrect cipher specification like "aes-999-cbc" instead of valid options like "aes-256-cbc" will trigger this initialization error.

This error occurs when two or more modules require each other, creating a dependency loop. Node.js returns an incomplete module export to prevent infinite loops, resulting in undefined imports and runtime errors.

This error occurs when attempting to register multiple PerformanceObserver instances for the same entry type in Node.js. Only one observer can monitor a specific entry type at a time, and duplicate registrations trigger an assertion failure that can crash the process.

Node.js shows a deprecation warning when code uses the built-in punycode module. This module has been deprecated since Node.js v7 and became a runtime deprecation in v21, warning that it will be removed in a future major version.

This error occurs in Node.js cluster mode when a worker process fails to exit within the expected timeout period after disconnect() is called. It typically indicates that the worker has open connections or pending operations preventing graceful shutdown.

This error occurs when a Transform stream's _flush() method encounters an error during stream finalization. The flush method is called after all data has been processed but before the stream ends, and errors here indicate failed cleanup operations or final transformations.

This error occurs when the Content-Length header value does not match the actual size of the response body received. It typically happens when the server sends an incorrect header, a proxy modifies the response without updating headers, or compression is applied inconsistently.

This error occurs when a web application tries to make a cross-origin HTTP request, but the server does not allow requests from the requesting origin. Browsers enforce CORS (Cross-Origin Resource Sharing) to protect users from potentially malicious cross-origin requests.

This error occurs when a Node.js TLS client refuses to connect because the server offers Diffie-Hellman key exchange parameters smaller than the minimum security threshold (typically 1024 bits). Modern OpenSSL versions reject weak DH groups to protect against cryptographic attacks like Logjam.

This error occurs when Node.js's zlib module fails to decompress data due to corrupted input, incorrect compression format, or header mismatches. The decompression algorithm encounters data that doesn't conform to the expected zlib/gzip format.

This error occurs when a Node.js writable stream fails to emit the drain event after write() returns false, indicating a backpressure handling failure. The stream's internal buffer is full but never signals when it's safe to resume writing, leading to frozen writes, memory buildup, or application hangs. Proper backpressure handling requires correctly listening for and responding to the drain event.

The "Not implemented" error occurs when attempting to use a feature, method, or API that has not been implemented in the current environment, library, or Node.js version. This can happen with custom stream implementations, platform-specific functions, or browser APIs in testing environments.

This error occurs when you attempt to use an unsupported or misspelled algorithm name with Node.js crypto module functions like createHash() or createHmac(). The algorithm name must match one of the hash algorithms available in your Node.js/OpenSSL installation.

This error occurs when Node.js attempts to write to a file or directory that resides on a read-only filesystem. It commonly happens in Docker containers with read-only root filesystems, mounted volumes with incorrect permissions, or filesystems explicitly mounted as read-only for security reasons.

This error occurs when a Node.js application attempts to connect to a TCP port but the connection is actively refused because no service is listening on that port. It commonly happens with database connections, API calls to localhost, or inter-service communication when the target server is not running or the port configuration is incorrect.

An uncaught exception occurs when a JavaScript error is thrown but not caught by any try-catch block or error handler, causing the application to crash. This indicates the application is in an undefined state and must be properly handled to prevent data corruption.

EHOSTDOWN is a socket connection error indicating the remote host is down or unreachable at the network layer. This error occurs when Node.js receives status information from the underlying communication services that the target host is down.

This error occurs when attempting to use CommonJS require() syntax in code being treated as an ES module. Node.js uses different module systems, and require() is not available in ES module scope.

This error occurs when you specify a character encoding that Node.js does not natively support, such as "utf-16" or a misspelled encoding name. Node.js supports specific encodings like utf8, utf16le, ascii, and base64.

This error occurs when Node.js fails to complete a TLS handshake during an HTTPS or secure WebSocket connection. The client and server cannot agree on compatible encryption protocols, cipher suites, or certificate parameters, causing the secure connection to be rejected.

This error occurs when attempting to chain .then() on a value that is undefined instead of a Promise. It typically happens when a function fails to return a Promise, breaking the promise chain.

This error occurs when both sides of a Node.js duplex stream (readable and writable) fail or close prematurely before completing data transfer. It commonly happens due to improper error handling, missing event listeners, or abrupt connection terminations in network streams, transform streams, or bidirectional pipes.

The ENETUNREACH error occurs when Node.js cannot establish a network connection because the destination network is unreachable. This typically indicates routing problems, network interface issues, or firewall restrictions preventing your application from reaching the target host.

The EHOSTUNREACH error occurs when Node.js attempts to establish a TCP connection but cannot find any network route to reach the target host. This typically indicates network configuration issues, firewall blocks, or an unreachable server.

This error occurs when the operating system runs out of buffer space for network operations, typically during heavy socket operations or large data transfers. It indicates system-level resource exhaustion rather than a code-level bug.

The ENOENT (Error NO ENTry) error occurs when Node.js attempts to access a file or directory that does not exist at the specified path. This is one of the most common filesystem errors and typically results from incorrect file paths, relative path confusion, or missing files. Understanding how Node.js resolves paths is essential to fixing this error permanently.

This error occurs when Node.js attempts a file system operation that the operating system denies due to insufficient permissions. It commonly happens during chmod, rename, unlink, or write operations, particularly on Windows with antivirus software or on Unix-like systems with incorrect file ownership.

This error occurs when attempting to remove a directory that contains files or subdirectories using fs.rmdir() or fs.rmdirSync(). Node.js refuses to delete non-empty directories unless the recursive option is enabled.

This error occurs when Node.js file system operations expect a directory path but receive a file path instead. It commonly appears with fs.readdir(), fs.scandir(), or file watching utilities.

The ESRCH error occurs when attempting to send a signal to a process that no longer exists. This typically happens with process.kill() or child process operations when the target process has already exited.

This error occurs when Node.js child_process.exec() tries to execute a command that cannot be found by the shell (/bin/sh). The shell either cannot locate the executable in PATH or the command does not exist on the system.

ETIMEDOUT occurs when a network operation in Node.js does not complete within the specified or default time limit. This typically happens during HTTP requests, database connections, or socket operations when the remote server fails to respond in time.

This warning appears when using the worker_threads module in Node.js versions prior to v12, where the feature was still experimental. Worker threads became stable in Node.js v12 LTS, so upgrading to v12+ is the primary solution.

This error occurs when trying to use the CommonJS global __filename in an ES module. ES modules use a different approach to access file paths and do not provide __filename by default.

This error occurs when a server acting as a gateway or proxy does not receive a timely response from an upstream server. It commonly happens when your Node.js application makes requests to external APIs, databases, or microservices that take too long to respond, exceeding the configured timeout limits.

This error occurs when child_process.execFile() attempts to execute a script file that lacks executable permissions. The Node.js process cannot spawn the file as a child process because the operating system denies execution.

Occurs when Node.js cannot authenticate with MySQL due to incorrect credentials, insufficient permissions, or authentication plugin mismatches.

This error occurs when you pass an argument of the wrong type to a Node.js function that expects a string. It's commonly triggered when file system methods receive a number, undefined, null, or object instead of a string path.

This error occurs when attempting to allocate a Node.js Buffer with an invalid size—typically negative, zero, or exceeding platform limits. Buffer.alloc() and Buffer.allocUnsafe() enforce strict validation to prevent memory allocation failures.

This error occurs when Node.js tries to parse your package.json file but finds invalid JSON syntax. Common culprits include missing commas, mismatched quotes, or trailing commas. The error can be fixed by validating the JSON structure and correcting syntax errors.

This error occurs when a custom iterator's next() method returns a non-object value instead of the required {value, done} object. Common in stream implementations and async iterators.

This error occurs when attempting to encode or decode data containing characters outside the ASCII range (0-127) using ASCII encoding. ASCII is a 7-bit character encoding that cannot represent extended characters, Unicode characters, or any values above 127.

This error occurs when Node.js cannot locate a module specified in a require() or import statement. Common causes include typos in the file path, missing files, incorrect relative paths, or uninstalled dependencies. The error typically happens with local file imports that point to non-existent paths or third-party packages that haven't been installed.

This error occurs when attempting to create a Buffer with a malformed hexadecimal string. The hex string must contain an even number of valid hexadecimal characters, with each pair representing a single byte.

This error occurs when spawning a detached child process in Node.js without properly configuring the stdio option. Detached processes require specific stdio settings to run independently from their parent process.

This error occurs when a Node.js HTTP client receives an HTTP response with a version string that the parser cannot recognize or does not support. It typically indicates a protocol mismatch, malformed server response, or incompatibility with an intermediary like a proxy or load balancer.

This error occurs when attempting to send messages over an IPC (Inter-Process Communication) channel that has already been closed or destroyed. It typically happens when a child process exits unexpectedly or the parent-child communication link is severed before all pending messages are delivered.

This error occurs when Node.js HTTP client receives a malformed HTTP response that does not conform to the HTTP specification. The error happens at the socket parser level when headers or the status line are invalid, often due to strict validation in Node.js v12+.

This error occurs when a POST or PUT request sends more data than Express's body-parser middleware allows. By default, Express limits JSON payloads to 100KB. Increase the limit in your middleware configuration to fix this.

Express requires error-handling middleware to have exactly four parameters: (err, req, res, next). Without all four parameters, Express treats the function as regular middleware instead of an error handler. This error occurs when your error handler doesn't follow the correct signature.

This error occurs when your Express or Node.js application attempts to modify HTTP response headers after the response body has already been sent to the client. This typically happens when multiple responses are sent per request or when headers are set after res.send(), res.json(), or similar methods.

The Node.js domain module is deprecated and should not be used in new code. This warning appears when you import or use the domain module. Use async_hooks or AsyncResource instead for proper async context tracking.

This error occurs when Express.static() middleware is configured to serve files from a directory that doesn't exist. The application fails to start because the specified path cannot be found on the filesystem.

This Fastify error occurs when you attempt to send a response twice on the same request. Once reply.send() has been called, the response is finalized and cannot be sent again. Ensure each route handler sends a response only once.

This error occurs in Fastify when you try to register a decorator (plugin, hook, or utility method) with a name that already exists. Fastify prevents duplicate decorator registration to avoid silent overwrites. The fix involves checking for existing decorators, using unique names, or explicitly overwriting when intentional.

The FST_ERR_HOOK_TIMEOUT error occurs when a Fastify hook (onRequest, onSend, etc.) takes longer than the allowed timeout to complete. This error indicates that your hook is either performing long-running operations or is stuck in an infinite loop. Resolving this requires optimizing the hook code or adjusting timeout configuration.

This error occurs when a client makes a request to an Express server for a URL path that does not match any defined routes. Express returns a 404 Not Found HTTP status code, indicating the requested resource could not be found on the server.

This error occurs when fs.copyFile() is called with the COPYFILE_EXCL flag and the destination file already exists. The COPYFILE_EXCL flag is a safety mechanism that prevents overwriting existing files, causing the operation to fail if the destination path is occupied.

This error occurs when fs.mkdir() or fs.mkdirSync() attempts to create a directory at a path where a file already exists. Node.js cannot create a directory with the same name as an existing file, causing the operation to fail with EEXIST.

This error occurs when Node.js attempts to create a symbolic link on Windows without administrator privileges. Windows restricts symlink creation to admin accounts or users with specific developer mode permissions. The error commonly appears when using fs.symlink() or tools that auto-link dependencies, especially in development environments or CI/CD pipelines.

This error occurs when an HTTP/2 frame payload exceeds the maximum allowed frame size limit. HTTP/2 enforces strict frame size constraints (default 16KB), and this error indicates the server or client sent a frame that violates these limits, preventing the connection from continuing.

This error occurs when an HTTP/2 connection violates flow control rules by sending more data than the peer is willing to accept. Flow control in HTTP/2 prevents overwhelming the receiver by using a window-based system. The error happens when the sender exceeds the advertised window size or improperly manages window updates, causing the protocol to abort the connection.

This error occurs when Node.js HTTP/2 session receives a SETTINGS frame that does not comply with HTTP/2 protocol specifications. The settings frame may contain invalid parameter IDs, out-of-range values, or malformed data that the HTTP/2 parser cannot process.

Express session middleware fails when the session store is not properly initialized or configured. This error occurs when express-session cannot establish a connection to the session storage backend (Memory, Redis, MongoDB, etc.). The application needs a compatible session store middleware to persist user sessions across requests.

This error occurs when Express cannot locate the view engine you specified in your application. It typically happens when the view engine package is not installed, the engine name is misspelled, or the engine is not properly registered.

This warning indicates that more than the default 10 listeners have been added to an EventEmitter without being removed, potentially causing memory leaks. Node.js warns you to either remove unused listeners, use emitter.setMaxListeners() to increase the limit, or refactor to avoid accumulating listeners.

This error occurs when an EventEmitter instance emits an "error" event but no listener is registered to handle it. Node.js will throw an unhandled error, crashing the process, because error events have special handling requirements in the EventEmitter API.

This error occurs when multiple cluster workers attempt to bind to the same port incorrectly, or when a worker tries to reopen a listener on a port it previously closed, causing EADDRINUSE conflicts in the cluster environment.

This error occurs when a DNS server fails to complete a hostname lookup in Node.js. It typically indicates DNS server configuration issues, DNSSEC validation failures, or network connectivity problems between your application and the DNS resolver.

This error occurs when JavaScript tries to call an async function that hasn't been properly defined or declared. Most commonly, it's caused by missing semicolons between statements, where the parser misinterprets code structure.

This Fastify error occurs when your route handler or hook attempts to send a response multiple times for the same HTTP request. Fastify prevents duplicate responses, which would cause protocol violations and unpredictable client behavior.

This error occurs when Node.js fails to generate RSA key pairs using the crypto module. It typically results from memory constraints, invalid parameters, system resource limits, or OpenSSL library issues.

This error occurs when you pass an unsupported or invalid encoding name to a Node.js readable stream's setEncoding() method. Common causes include typos in encoding names, using encodings that aren't built-in to Node.js, or specifying an encoding that doesn't match your data format.

This error occurs when Node.js cannot locate the TLS certificate files required to establish a secure connection. It typically indicates missing, misconfigured, or inaccessible certificate paths in your HTTPS/TLS server setup.

This error occurs when stream operations attempt to access the length property of a null chunk, typically when null values are written to streams or when stream buffers contain null entries.

This error occurs when Node.js attempts to open a file with an invalid path argument. Common causes include malformed file paths, invalid characters in filenames (especially on Windows), and filesystem issues on external drives.

This error occurs when you attempt to configure a Node.js stream with an invalid readableLength value. readableLength must be a positive integer (greater than 0) when specified. Invalid values like negative numbers, zero, strings, or non-integer values will trigger this TypeError.

This error occurs when you configure a Node.js stream with an invalid highWaterMark value. highWaterMark controls the internal buffer threshold for stream backpressure, and it must be a positive integer (0 or greater). Invalid values like negative numbers, strings, or numbers exceeding 1GiB will trigger this RangeError.

This error indicates an internal bug in Node.js or incorrect usage of Node.js internals. When an assertion in the Node.js engine fails, it results in a crash with details about what went wrong. These errors are typically caused by edge cases in network operations, module loading, or worker thread handling.

This error occurs when a Node.js process attempts to change its user identity using process.setuid() without sufficient privileges. The operation requires either running as root or having the CAP_SETUID Linux capability.

This error occurs when Buffer.concat() receives arguments that are not Buffer or Uint8Array instances. The method expects an array containing only Buffer or Uint8Array objects, but receives strings, plain objects, or other incompatible types instead.

The Node.js cluster module fails to create a new worker process, typically due to system resource limits being reached. This commonly occurs when the process has exhausted available file descriptors, memory, or the maximum number of allowed processes.

This error occurs when a Node.js process attempts to access a file, directory, or port without the necessary permissions. It commonly happens during file operations, npm installations, or when trying to bind to privileged ports below 1024.

This error occurs when your Node.js process has reached the operating system limit for the maximum number of file descriptors it can open simultaneously. File descriptors are used for files, network sockets, pipes, and other I/O resources.

This error occurs when Node.js cannot successfully initialize a Worker thread during startup. It typically indicates problems with module loading, resource constraints, code errors in the worker file, or circular dependencies between the main thread and worker.

This error occurs in Express.js when middleware or a route handler calls the next() function more than once during a single request cycle. Calling next() twice causes Express to attempt to send the response multiple times, leading to unexpected behavior and cryptic errors.

This error occurs when code attempts to interact with a listener that was already invoked through the once() method. The once() method registers a one-time listener that automatically removes itself after the first event emission, causing issues if code tries to access it again.

This error occurs when fs.watch() exceeds the operating system limit for file watchers. File system watchers consume limited system resources, and watching too many files simultaneously exhausts these limits.