I have no way to reproduce this, does this still happen? It sounds like a nouveau driver issue. Perhaps someone from Ubuntu studio can chime in.
** Changed in: plasma-workspace (Ubuntu) Status: New => Incomplete -- You received this bug notification because you are a member of Kubuntu Bugs, which is subscribed to plasma-workspace in Ubuntu. https://bugs.launchpad.net/bugs/2043446 Title: AssertionMessage: plasmashell: ../nouveau/pushbuf.c:730: nouveau_pushbuf_data: Assertion `kref' failed. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/plasma-workspace/+bug/2043446/+subscriptions -- kubuntu-bugs mailing list kubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/kubuntu-bugs