ThijssjihT: As I said before, I did the quest infested mine, but I didn't finish it yet. Trying to finish it, also gave me the same crash to desktop. Also, in the conversation with (I forgot his name) in the royal blood quest, I got a couple of black screens, but the conversation continues.
I think it's not a defect in the game, but in my installation.
I reinstalled the game, applied the patches, and as far as I can tell, everything works now.
Hans, thank you for helping me!
EDIT:
I can't seem to mark my own solution as a solution. How can I close this topic?