You've posted this in a Beyond Divinity forum; it should be in the D2:ED
Help/Tips/Tricks forum (I assume you were looking at the mention of 'second installment' in the BD forum group description, but Divinity 2 is actually the third game in the series).
I don't know if there are any know issues or solutions for startup problems with D2:ED, as I am waiting for the official English release.
If you have applied the language hack, you may want to un-install and re-install the game, then try starting it in German, just to check if that is part of the problem, or not.
Are you shutting down all non-essential programs (especially anti-virus) before starting the game?
The topic
Crashes, no support...... may contain some helpful troubleshooting tips.