Having trouble with crashes during combat in the late game

I'm hundreds of turns into the game and my combats have grown increasingly unstable. I actually have one hero who crashes the game every time she tries to attack. I eventually had to send her to a city for fear that I'd accidentally have her try and attack.

A different situation: I'm trying to fight this giant bear without using auto-combat so I don't waste a bunch of mana, but every time the bear attacks the game crashes.

I also am not getting crash-file zips for these combat crashes.

 I get an hourglass, a freeze, and then the windows bingbong message.