To ensure the maps work correctly without "missing texture" errors (the infamous pink/black checkers), you usually need specific assets:
Most maps are just the building. You typically need to download separately, such as the FNaF Ragdoll Pack Why is the map pitch black? Make sure you have Counter-Strike: Source mounted or the specific map content pack installed. Steam Community If you're having trouble with missing textures broken doors fnaf+1+map+gmod+link