I just had a CTD as I handed in a contract. It only happened once. After reloading I could complete it.
Undead scourge – clear 2 enemy camps. I encountered the first camp and the objective changed for me to hunt down some necromancers. After that fight I could finish the contract, but didn’t. I went for the other camp instead. Then one more fight with some spawns from second camp and back to hand in the contract.
I attached a screenshot of the error message with stacktrace and the log. Maybe you can figure out what happened.