I had a map "Defense" where it would crash upon the game starting. It only started doing it after I beat it though. It was a map where you were behind walls with buildings blocking 3 parts and the computer had tons of forts and they would make 3 range lightning peons. They made 1000 peons over time and you had to kill them all with 2 peasants each and repair the buildings. The crashing could be different things, maybe too many units, or some error with the terrain, when the map crashes the game it is hard to figure out sometimes you're right. I finally ended up getting my Defense one to work recently by using a saved backup I had of the final version from years back. Do you have any older close to or finished versions?