No i can't play any zombie maps exept custom maps i tried playing the story ( i only played the last map to get the credits for nacht) but it always crashed *spoiler* when i took the russian flag and placed it in the ground

I can't play any modded maps for some reason there is only one map that i can play its cs_assault but every other map (dead ship, Requiem, Sog etc.) doesn't start. In the game i click on mods and launch Dead Ship than i click on play solo it loads but after its done loading im back to the ...