Can you get us a picture of your map, so we can see if there really is way too much props placed.
Have you tried to start your map by using blank_1-200? Does your pc crash then? What kind of pc you are running?
no offense deathwhisper, but that is rather large for siege or any other gamemode.
also, that is a LOT of props, and some are being stretched a lot etc....might be causing issues.