Okay it’s like this:
The “Saving” Screen shows up and remains for I guess half a minute and the timeout error shows up. After trying to save my game again 2 or 3 times, only the “Saving” Screen shows up and the client screen freezes!
(Sadly, I’ve got a new problem now: I can’t load my new project! It’s my entry for “The Legend of the 3 orbs”-Challenge! And now I can’t work on it anymore… -.- I tried to load the file a few times now. The other files can be loaded though!)