Crash after returning from Mornwatch sidequests

Hello,

I was returning through the crossroads from the necropolis after doing the quest with the wisps and the one with the Venatori there. Some undead just showed up in the crossroad and the characters mention the blight spreading there. 

When I try to return to the lighthouse, the game crashes.

The crash dump exception information is "The thread tried to read from or write to a virtual address for which it does not have the appropriate access."