Missing models/textures on several maps

I’ll use RP Apocalypse as an example

http://puu.sh/3057e.jpg

Basically, many maps I have installed are missing textures and models, even though I have CSS, HL2, HL2 Ep1, and HL2 Ep2 mounted ingame.
I don’t really understand, I’ve installed everything correctly and this crap still happens.

SteamPipe is causing trouble, make sure you opt into the Beta in all Source games.

  1. Right-click on a Half-Life game in the Library
  2. Go to Properties
  3. Enter the Betas tab
  4. Choose to opt into the SteamPipe Beta
  5. Try starting the game, and let it convert if you get a message about such.

That fixed it, thank you.