There are special abilities that always seem to freeze the game, in tactical battle, for me. v0.86.
Often it's a permamemt freeze forcing me to kill the game process. It happens with a freshly loaded game too so not an out of memory issue.
The abilities I know cause this: Maul, both used by bears for example or if I have a weapon with maul. Sometimes if I wait it eventually executes at which point the game is ok until the next use of maul.
The other ability I've run into is one used by a forsaken. Unfortunately not sure what ability cause the game always freezes permanently and they have good initiative!
This is a game killer for me right now cause I can't fight these units unless I can kill them before they have a chance to attack. Very difficult with the forsaken on a small tactical map because they often move first and can reach me immediately.
Update: As it turns out the Forsaken Martyr has a weapon with maul, so it's maul again causing the issue.