Comment # 3 on bug 978454 from Dominique Leuenberger

(In reply to Dominique Leuenberger from comment #2)
> (In reply to Egbert Eich from comment #1)
> > What's your DEFAULT_WM setting in /etc/sysconfig/windowmanager?
> 
> DEFAULT_WM="kde4"
> 
> (this was from an openQA run, updating an old system to TW)

Indeed, toggling this to 'plasma5' works (I though have though about that one).

So the question would be how to avoid obsolete values in there on system
upgrades...