The suggestion from Igor finally worked although not right away in my case :)
These two: sudo apt install --only-upgrade ubuntu-release-upgrader-core sudo apt dist-upgrade --allow-downgrades Managed, probably, to get the system past the error of this ticket but afterwards I wasn't able to login in KDE at all. Sddm started and after entering password, the logs showed sddm: Message received from greeter: Login sddm: Invalid session "" Actually there was no session to select on the login screen. So in the alt+f3-4-(whatever) console: apt install plasma-workspace-wayland and after this the result was that I was albel to login but essential stuff from the desktop was missing, like activityswitcher, etc. So this finally made Plasma work again: apt install plasma-desktop Haven't investigated it further but I suppose somewhere in the process of upgrading and all the stuff that happened afterwards, that plasma- desktop was messed up. Now all seems to work. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2059779 Title: can't update in discover To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/ubuntu-release-upgrader/+bug/2059779/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
