How to fix dpkg: serious warning: files list file for package 'package' is missing final newline in APT

Open a terminal and look at the files in /var/lib/dpkg/info/:

ls -la /var/lib/dpkg/info/ | grep -E "\.list$"

Note the package name mentioned in the error message. Look for the corresponding .list file, such as /var/lib/dpkg/info/package-name.list.

Use cat or hexdump to inspect the file content:

cat /var/lib/dpkg/info/package-name.list | head -20

If you see normal text paths, the file may only be missing the final newline. If you see hex characters or gibberish, the file is corrupted and should be deleted.

If the file contains valid text but just lacks a final newline, you can add it:

echo "" >> /var/lib/dpkg/info/package-name.list

This appends a newline to the end of the file, which often resolves the warning.

If the file contains binary garbage or invalid data, delete it and related files:

sudo rm /var/lib/dpkg/info/package-name.list
sudo rm /var/lib/dpkg/info/package-name.md5sums

After removing the file, run:

sudo dpkg --configure -a

After fixing the corrupted file, reconfigure all packages and update:

sudo dpkg --configure -a
sudo apt update
sudo apt upgrade

The dpkg --configure -a command processes any pending package configurations and should resolve the dpkg state.

If the package still has issues after removing its .list file, reinstall it:

sudo apt install --reinstall package-name

This ensures the package metadata is properly recreated.