Comment # 2 on bug 1123638 from Axel Braun

(In reply to Wolfgang Bauer from comment #1)
> Sounds very much like https://bugs.kde.org/show_bug.cgi?id=374864, I think.
> 
> Did you enable the option "Capture the current pop-up only"?

Yes 

> Does it work if you disable it, or disable compositing (e.g. via
> Shift+Alt+F12)?

For both options it works, but if compositing is disabled, there is basically
nothing in the screenshot (blank). So only disable 'nur aktuelles Aufklappmen�'
fixes it.
Thanks!