Well, well...
Now, the game crashes at some point during the turn of the turquoise AI (I suspect it happens when it tries to attack the green Lucretia, by the way, where is she and what is she doing?). This happens after the bridge is opened, but not immediately, but after a couple of turns. I'll try to attack the Necromancer later - I'll go to the dungeon for a week or two.

Added 1 hour 20 minutes ago
Damn, the same thing - after some number of turns, the turquoise AI does something that causes the game to crash. I understand about Lucretia - she should have come to visit, but she didn't: besides Kaspar from the Necromancer, no one came.
P.S. I tried to enable the console - unfortunately, the crash is severe, the game window closes immediately.