Crash to desktop when playing campaign battles!

I always get a crash to desktop, well a black screen that I can't get rid of so I restart my computer. I just started a campaign and this happens everytime, what can I do to fix this?

Anyone have a solution?

Try reinstalling. Wht units do you use when fighting custom battles?

They were mostly just a set from the starting campaign, from the capital city along with a couple new ones, forget what there called but there the cheaper 1 turn units, may have had a heavy I don't remember. Im playing Reikland I think its called. This mod is annoying me a lot, might just go to Fourth Age! Been weeks and haven't played this yet cause of this.