My apologies if this one has already been brought up, but the game freezes and thows an error if you click along or slightly above the yellow border while in the wizard's castle screen in the green highlighted area. Click anywhere along that yellow border or slightly above in the green highlight and you should get the error.
I can verify this error happens in different area along the top yellow border edge in the Warlock, Witch, Barbarian, Wizard, and Dervish towns. I cannot duplicate the error in the Sorceress, Knight, or Necromancer towns. The area the error happens seems to vary by town. Just try any of the factions I mention have the problem above and start left clicking rapidly while moving the mouse pointer along that upper yellow border edge as in my image and you should crash on those 5 factions.
I gave the wizard example here as it seems particularly bad and always happens when clicking in the green area. I believe the Warlock click crash occurs directly above he castle central tower image.
Any idea what is up with that? I came across the error just because I often accidentally click near that line on occasion when wanting to see how many creatures are hireable in the Wiz town. Then I thought I would check the rest and came up with the list above.