Ahso ok. Ich schätze mal du musst den gamecontent noch extrahieren.. sonst stehen diese im editor nicht zur verfügung.
Habe im Forum von denen einen Thread gefunden (lenglisch ):
http://www.zombiepanic.org/forums/showthread.php?t=12232
Zitat: ´Since being released on Steam, Zombie Panic! Source requires these files to be extracted from the GCF and stored locally in the ZP: S folder. If you don’t do this Hammer won’t be able to see custom textures and models as well as not being able to use the mapping .FGD. For some reason though, this doesn’t apply to sounds.