RTB might be the cause of it, if you have it. When I had RTB, I kept crashing whenever I hosted servers with either a very specific combination of addons or a certain number of addons. After deleting RTB, the crashing stopped.
could be the string overflow issues
RTB puts a list of the enabled addons together in a string, and if it's too big the game will crash
I think it may be an addon, but I got like 1000
what debugging have you tried?
have you tried hosting with only defaults enabled?
have you tried a clean install?
does the console show any errors?