The game in skirmish and first missions of campaign works perfectly smooth and without any crashes. But every time my Empire campaign freezes at mission "Retribution". Greenskins campaign freezes at mission two.
I have nVidia graphics card and all updates installed. I tried with setting the video options in the game too. I have no more ideas what's wrong going on. I see some Youtubers play a walkthroughs with the GoG version of the game but no one of them did reply to my comments.

Came here to find a solution, but after some tinkering, I found that when the game freezes at a beginning of a mission, all you have to do is alt-tab to desktop, then alt-tab back, wait out the black screen and the game should resume. Hope it helps!