After speaking with dandelion at like side cinematic enters at loading screen game says save file missing or corrupted I tried several times and I played act 4 severel times everytime same thing happenend. What shoulf I do ?
Hmm... after searching for similar issues around the web, it seems reinstalling the game is your best option. Back up your saves before doing it, though.
You could also try to verify/repair your installation via GOG/Steam, assuming you're using one of those platforms for the game. Didn't see any suggestions for that course of action, but it might be worth a shot.
From what I've read on the internet from people with a similar problem it may be caused by having exeeded the maximum save game capacity (100MB). If that is the problem in your case it should help to delete a few of your earlier save games.