I believe you've only disabled the PPA and not actually removed the packages which you have installed from it. You could confirm this by running the following:
dpkg -l | grep ii.*oibaf If you still have some installed please use 'ppa-purge' to remove them, however you'll have to reenable the PPA for ppa-purge to work. ** Changed in: ubuntu-release-upgrader (Ubuntu) Status: New => Incomplete -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1872927 Title: Might be due to nvidia drivers? To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/ubuntu-release-upgrader/+bug/1872927/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs