Siege crash

[The Devourer]

Every time i try to fight a siege battle in kingdoms, whether in campaign or a custom battle, my game crashes to desktop. I was wondering if anyone had any idea as to why this is happening, and if so what i could do about it. Every other aspect of the game seems to work fine, but the game always crashes on a siege. Any help appreciated.

[The Devourer]

Well, i've reinstalled the main game and the brittish expansion, still keeps happening.