Thanks Raymond and Wolfgang for your helpful tips!
I indeed usually update through Yast. Updating through zypper did the trick!
2015-09-15 19:21 GMT+02:00 Wolfgang Bauer firstname.lastname@example.org:
Am Dienstag, 15. September 2015, 18:26:32 schrieben Sie:
@Wolfgang: I made the suggested changes and rebooted. Still hangs...
Ok, then please revert the change. This should only be done if necessary, as it negatively impacts graphics performance.
@Raymond: plasmashell produces an error message when started from Konsole:
plasmashell: symbol lookup error: plasmashell: undefined symbol: _ZN8KWayland6Client8Registry20plasmaShellAnnouncedEjj
Does this mean anything to anyone?
Yes. You still have the old libKWaylandServer and libKWaylandClient packages installed, i.e. your system is not fully updated. Install kwayland instead (this should remove the former), and your problem should be fixed.
How did you do the update? zypper should automatically replace the former packages by the latter one.
I know from some forum threads though that some users try to use YaST (All in this list->Update, if newer version available) to keep their Tumbleweed system up-to-date, and that doesn't do "the right thing" in this case.
Kind Regards, Wolfgang