This game crashes during combat with a doppelganger. I am not sure if it is either when I use mesmerize on it, a failed mesmerize attempt, finishing it off with mesmerize, or the doppelganger tries to use mesmerize on my party.
Edit: I figured it out now. The doppelganger fight make your allies accidentally attack Pacha, which works correctly for normal attack and spells. However, when your allies use mesmerize or seduction based spell and it accidentally hit Pacha, then the error occurs.