It seems still an issue if a user installed Focal by 20.04.1 before then he buy and then plug-in a new Nvidia card to his PC then install nvidia driver. The user will still get this error.
The version(2.0.4) of fixed apt not in focal-security, so user not updated apt manually will still get the problem. root@7b676b5fb787:/# apt-cache policy apt apt: Installed: 2.0.5 Candidate: 2.0.5 Version table: *** 2.0.5 500 500 http://tw.archive.ubuntu.com/ubuntu focal-updates/main amd64 Packages 100 /var/lib/dpkg/status 2.0.2ubuntu0.2 500 500 http://security.ubuntu.com/ubuntu focal-security/main amd64 Packages 2.0.2 500 500 http://tw.archive.ubuntu.com/ubuntu focal/main amd64 Packages -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1923150 Title: unexpected error pop-up after 'apt install nvidia-driver-455' To manage notifications about this bug go to: https://bugs.launchpad.net/oem-priority/+bug/1923150/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs