@ bitbull: I honestly think this is the outcome of bug 1451728. Tending to mark as duplicate, since there is no real relation to SDDM.
A lot of things went wrong during your attempt to deinstall the kubuntu- desktop, saying so after going through the attached DpkgHistory.log Given the fact that probably the package-manager in use wouldn't give visual feedback, the log provided sufficient information valid for a multi-desktop environement (as it's easy to install, but hard to get rid of) -> Make sure to install/switch to GDM. And in final make sure to reinstall gnome-desktop, since the deinstallation teared away most needed packages for a functioning environment. Not knowing if u have come back to a functional desktop, I would recommend to join the ubuntusers.de Forum for assistance. There are great people with a broad knowledge considered to help. Anyway your system should be recoverable with the chroot-method by using a Live-CD (same release and architecture). This is described well in https://wiki.ubuntuusers.de/chroot/Live-CD/ I can honestly not understand why Kubuntu-devs didn't make accounts- plugins/kaccounts-providers conflict, when this error appeared. This would have avoided a considered amount of troubles for a lot of people. The common ratio of bugs beeing reported is 1:100 to the ratio of people beeing affected. Having said so, you are welcome if you need any further assistance to recover your system. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1548817 Title: package sddm (not installed) failed to install/upgrade: Unterprozess installiertes post-removal-Skript gab den Fehlerwert 128 zurück To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/sddm/+bug/1548817/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs