> @Dirk: can you please try to run:
> 1) run "kscreenlocker_greet --testing" from a konsole
> 2) turn off the display
>
> Afterwards please tell us whether the application exited or not. If it did,
> please add the debug output from the konsole.
I followed the procedure.
after switching the monitor on again the kscreenlocker_greet was gone.
I attach the output of "kscreenlocker_greet --testing" and appended to it the
content of .xsession-errors-:0
Also some check for the files which can not be opened according to the output
of kscreenlocker_greet.