my friend posted this about his server once, If anyone is crashing while connecting to [TKZ], there was apparently an update to TF2 that results in Garry's Mod crashing to desktop when connecting to servers with TF2 mounted. so just unmount tf2

try unmounting tf2 from your gmod

yea there is a glitch on tf2 where its update is fuking everyone over, it happened to me once