Cannot open Trados Studio 2015. Error Message: Dienst SDL.Desktop.Platform.CommandBars. ActionService konnte nicht gestartet werden.

I cannot open Trados Studio 2015 although it functioned well till yesterday and I did not change anything.
Error Message is: Dienst SDL.Desktop.Platform.CommandBars. ActionService konnte nicht gestartet werden.
I tried to reinstall but same error.
Does anyone have an idea how to solve this problem?