I just did more testing. 1v1 doesn't crash for me, but 1v1v1 does. I couldn't upload the files it said something went wrong during compression.
Crashed at the start of an RTS battle, before the screen had fully faded in from black to the map, in Campaign mode where the campaign was a 1v1v1 (2 AI's).
2v2's, 3v1's and 1v1's do not have this problem, it's only when the Campaign has 3 or 4 factions that it crashes at the start of an RTS battle. Only factions of two countries were in the fight, perhaps the game is not sure where to start the other 1-2 factions that don't have any units in the fight.
I had the crash on 2v2 yesterday.
Just to be clear, did the game crash DURING the battle, but you could start it and play for a while, or did it crash right at the start, when the map was fading in from black?