HELP - Source games not mounting

[YankeeSamurai]

I have a bunch of source games (hl2 episodes, css, etc) installed on steam. I didn't have any problems until the Gmod 13 update, but now when I try to play gmod, I seem to be missing all hl2 episodic content. I'm missing a lot of textures and models and I can't find any settings or other methods to re-mount the missing content that I know I own.

Is there a way to re-mount the games? Or is there a different solution? I really am trying to get back into garrysmod, but I can't do that until I get all the nasty pink checkers and error signs resolved.

[Scratchie]

Click the little gamepad next to the gamemode.

[YankeeSamurai]

I feel immensely retarded now... I had assumed that button was for configuring a controller lol

Whelp, thanks a ton Karma. You can lock this if you wish.