If you try to play Garry’s Mod right after you download and install it you’ll have a bad time. If you join a multiplayer map you will most probably see the whole map covered on bright fuchsia/pink and black squares and ERROR messages.

That’s because the map requires textures not included in the standard installation. It seems that most gmod maps depend on a lot of Counter Strike textures, and for some weird reason they are not included in the installation.

Solution: you need to manually download and install all those textures.

Download this zip package, which contains all the most used textures. Wait a few seconds, close the ad, and download the file (~700MB). Find gmod installation folder. It should be somewhere, inside Steam’s folder. In my case, it was located at

C:\Program Files (x86)\Steam\steamapps\common\GarrysMod\garrysmod\addons Create a folder named CSS Content Addon . Extract the zip contents to the folder created in the previous step. Done. You should now have a maps , models , … folders inside CSS Content Addon .

For the complete guide on how to install and configure gmod, have a look at Configure Garry’s Mod (the complete guide).