You are attempting to upgrade from Ubuntu 20.04 to Ubuntu 21.10 (because Prompt=normal in /etc/udpate-manager/release-upgrades) yet your mirror of the Ubuntu archive does not contain information about Ubuntu 21.10 (impish). You'll need to either switch the mirror of the Ubuntu archive you are using to one that has impish, or modify /etc/update- manager/release-upgrades to contain "Prompt=lts".
** 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/1969983 Title: tried to do release upgrade via software manager and crashed with error about mirrors To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/ubuntu-release-upgrader/+bug/1969983/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs