SOLVED: I don't know why but finally it runs again...
I'm a bit desperate here:
I have RapidMiner 5 installed on my Win8 Laptop and it used to run without any problems. When I tried to start RapidMiner today nothing happened: RapidMiner doesn't launch, there is no error but simply nothing happens. I tried to run it as an admin > no effect. I re-installed it > no effect.
Does anyone have an idea what the problem might be?