I'm no expert on this kind of thing but the most likely cause is conflicting add-ons that you don't have on the steam version. Try disabling all of your add-ons (except default ones) and start a server. If you don't crash, then that means it is definitely a problem with add-ons. If you still crash, then I have no clue.
edit: also in the future try to keep help stuff in the help board