This machine have had cauldron for over a half year, continuously updating, moslty working very nice.
Now it suddenly decided KDE to die when desktop appear.
I have uninstalled everything KDE related i found, then installed task-kde.
As a workaround i have installed Mate, Ceinnamon, Gnome and they work.
Soeone please hint where to start fixing the problem - this is my wifes production machine and likes KDE absolutely best...
Also, gwenview and possibly other kde related apps hangs after their window appear.
Here is a link to download a .xsession-error generated first time a new user logs into KDE.
http://tribun.eu/owncloud/index.php/s/8Wit1CI6pdIPNiT
At this point the startup tune have played, mageiawelcome screen is up - and i can close it, but desktop is black, no background, menu, tray or anything.
The only working button is power button and i can choose to logout which works but takes a while.
EDIT: I can ctrl/alt/Fx to a console (grabbed the file there) /EDIT
Loggin into an old account is about the same, it shows desktop background, menu button, but some system tray icon is only half drawn and no dsktop icons, dead. Probably it just get further rendering desktop because mageiawelcome is disabled, before some process hangs it.
This is using Nvidia proprietary drivers, but it fails using nouveau too.