Playing heroes of might and magic 4 it keeps crashing during combat. It just freezes mid animation. Does anyone have the same problem and does anyone knoy what to do about it? It's on windows 10

Yes, this issue has been reported by several users.

Try the suggestions here:
https://www.gog.com/forum/heroes_of_might_and_magic_series/homm_4_crash_during_battle_windows_8
(second post has some useful info, plus additional suggestions in later posts).

Also, you could try my suggestion here. Though not specifically for freezing during battles, I had performance problems on highest resolution till I used DxWnd.
https://www.gog.com/forum/heroes_of_might_and_magic_series/heroes_4_freezing/post2