[Kupo91]

Do you have an idea what I could do wrong? Its quite a while when I used this tool probably I miss something.

Not really. You could try adding @logfile=tc.log to the command line and then see if it gets as far as writing anything to the logfile - if not then I suspect your Python environment is messed up somehow, try running a trivial Python script and see if that works any better. 

Thanks for your reply. I was able to get it running. But it didn't cache my game library. I use Rom Collection Browser to manage my games and it has a similar view like the video library. Is there a way to cache the posters and screenshots in this view, too?