Fatal Error during Campaign mission

As described in the title, I got a "Fatal Error" during the campaign. Everytime I defeat the Khorne Champion and the Plot goes on. Better said, when the Path to Terra Mission begins and I get the rewards for that. I cant get any further and it really sucks. I deinstalled the game, installed it again. Downloaded the newest drivers to my GPU and it still wont work. It says that it has a serious error with continuing the campaign mission. So what can I do? I just want to play the game.

Add a save file & dxdiag to your bug post, it will help devs find the rootcause of the bug