Gmod map models f*cked up (1 Viewer)

[Doc Piss]

I bought gmod yesterday and i noticed that in some maps the models were f*cked up like errors and purple-black everywhere (screeshot included) and i wanted to know if it's my shitty ass pc or the game or if there is a way to fix it.

Spoiler: Screenshot

 

[Cammy]

You need some other games for the models to properly render from what I've heard. You can download the needed files from some websites.

Obviously be careful they aren't malicious files.

 

[mosteraz]

The required games that are responsible for 99% of missing textures/errors are
Counter-Strike:Source & Half-Life 2 (including Episode 1 + 2).
If you own them already, install them and make sure you have them activated in Garry's Mod. (Main Menu - lower right side)

CS:S alone is sufficient for most maps though.