When I try to update it shows this error. I use Ubuntu 20.04

404 Not Found [IP: 91.189.95.85 80] Err:18 focal Release 404 Not Found [IP: 91.189.95.85 80] Traceback (most recent call last): File "/usr/lib/cnf-update-db", line 8, in from CommandNotFound.db.creator import DbCreator File "/usr/lib/python3/dist-packages/CommandNotFound/db/creator.py", line 11, in import apt_pkg ModuleNotFoundError: No module named 'apt_pkg' Reading package lists... Done E: The repository ' focal Release' does not have a Release file. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details. E: The repository ' focal Release' does not have a Release file. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details. E: Problem executing scripts APT::Update::Post-Invoke-Success 'if /usr/bin/test -w /var/lib/command-not-found/ -a -e /usr/lib/cnf-update-db; then /usr/lib/cnf-update-db > /dev/null; fi' E: Sub-process returned an error code

Before this happens to me, I upgraded my python3 version to 3.9.6. This is affect to some gnome app like gnome tweek(dosen't open). Currently I'm using kernel 5.10.

When I type wrong command it shows crash message

Traceback (most recent call last): File "/usr/lib/command-not-found", line 28, in from CommandNotFound import CommandNotFound File "/usr/lib/python3/dist-packages/CommandNotFound/CommandNotFound.py", line 19, in from CommandNotFound.db.db import SqliteDatabase File "/usr/lib/python3/dist-packages/CommandNotFound/db/db.py", line 5, in import apt_pkg ModuleNotFoundError: No module named 'apt_pkg'

Please help me to fix this.

1

1 Answer

Try to upgrade OS to repair broken package by type:

sudo apt-get dist-upgrade

or you can update packages URL. this article will help you