Garry's Mod Object Error

[warman1122888]

I just got Garry's mod and when i try out some objects to place and theres a big red glowing error letters sayng " ERROR "
nice to see they even made a object that shows tells you there's no texture for the item, but i recently joined some maps with a room full of objects but all of them were these big error signs and well.. thats the point when you decide to see if you can do sumtin' about it.
i thought maybe i need the source games, cuz thats where alot of items come from so i installed Counter Strike, half life 2 and team fortress 2, but it didnt seem to help at all.
if anybody had this problem and fixed it, please, i'd like to soo a gun in my hands instead of error above my head.

[NicoR0bin]

Which objects and maps and weapons are you trying to spawn o.o

Oh and you need to actually mount the games , not just install them