Solved
Battle happens when demolishing a town dwelling results in a crash if Sucubus's Charm ability successfully steals some troops
If you demolish a dwelling you owned in your town and decide to fight the troops in the dwelling (since you don't recruit them), Sucubbus's ability would still be activated and steal some troops from this battle.
If you see this before battle, it means your game will crash at the end of battle
Prepare to crash
Download the save game and debug for testing
Steps to reproduce with this save game:
- Enter the town With Crag
- Right-click on Mess Hall (the dwelling of Goblins)
- Confirm to demolish
- Don't agree to pay Gobloins for their leaving
- Accept the fight
- If you see that your commander attracts some goblins to the army, it means everything goes right. No matter whether you accept the goblins or not, the game crashes at the end of the battle.
Quick solution:
Can't see why Charming should activate in this case. I just disable it