Mounting CSS and Source Games to Fix Missing Textures
Why pink-and-black checkerboard textures and ERROR models appear, and how to mount Counter-Strike: Source and other Source games to fix them.
Why Textures Are Missing
GMod ships with its own content but relies on other Source Engine games for textures, models, and sounds used in popular maps and addons. The most common dependency is Counter-Strike: Source (CSS). Garry's Mod does not include CSS content because Valve does not license it for redistribution.
When a map or addon references a CSS texture that is not present, the Source Engine displays a pink-and-black checkerboard pattern in place of that texture. When a CSS model is missing, the engine renders the word ERROR in red at the model's location.
This is not a bug in GMod or your server — it is expected behavior when the required source content is absent.
What Content Is Commonly Missing
| Symptom | Root cause |
|---|---|
| Pink/black checkerboard textures | Missing material (.vmt / .vtf) files |
Red ERROR text models |
Missing mesh (.mdl) files |
| Missing map geometry | Missing BSP or map-referenced material |
CSS is the most frequently required game. Many popular DarkRP and sandbox maps (rp_downtown_v4c_v2, rp_evocity_v33x, cs_office) use CSS textures and props. Team Fortress 2 content is also sometimes required.
Installing CSS Dedicated Server Files
The CSS dedicated server provides all content files without requiring a CSS game license. Install it via SteamCMD using AppID 232330:
./steamcmd.sh +force_install_dir /home/container/css +login anonymous +app_update 232330 validate +quit
Note the install path — you will need it when configuring the mount file.
Configuring mount.cfg
The mount configuration file tells GMod where to find content from other Source games:
garrysmod/cfg/mount.cfg
Open the file. The default contents look like:
"mountcfg"
{
}
Remove the // comment prefixes from the games you want to mount and update the paths:
"mountcfg"
{
"cstrike" "/home/container/css/cstrike"
"tf" "/home/container/tf2/tf"
}
The path must point to the game's content folder (the folder containing materials/, models/, sounds/), not the root install directory. For CSS that folder is named cstrike.
Pterodactyl Path Considerations
On Pterodactyl, the server files are typically at /home/container/. If you install CSS alongside your GMod server:
/home/container/ ← GMod server root
/home/container/css/ ← CSS dedicated server files
/home/container/css/cstrike/ ← Path to use in mount.cfg
Verify the exact path by navigating the file manager in your panel and confirming materials/ exists inside the path you intend to use.
Applying the Mount
A full server restart is required after editing mount.cfg. exec mount.cfg does not reload the mount configuration.
After restart, verify CSS is mounted by testing a CSS map. Run in the console:
changelevel de_dust2
If the map loads without errors and displays correctly, CSS is mounted. de_dust2 is a CSS stock map that ships with the CSS server files.
Mounting TF2
TF2 content is required by some addon packs. Install TF2 dedicated server files using AppID 232250:
./steamcmd.sh +force_install_dir /home/container/tf2 +login anonymous +app_update 232250 validate +quit
Then add to mount.cfg:
"tf" "/home/container/tf2/tf"
Common Mounting Mistakes
Wrong path in mount.cfg: The path must point to the game subfolder (e.g., cstrike), not the root install. A path to /home/container/css/ instead of /home/container/css/cstrike/ will fail silently.
Comments not removed: Double-slashes // must be removed from lines you want active. A line with // is a comment and is ignored.
Restart not performed: mount.cfg changes require a full restart, not just a map change.
Wrong AppID for CSS: Use AppID 232330 (CSS dedicated server), not the client AppID. The client game requires a Steam account that owns CSS.
FastDL and Mounted Content
FastDL does not serve content from mounted games — it serves custom content you have uploaded to your CDN. Clients who do not own CSS still need CSS content for their client. The recommended approach for public servers is to use Workshop addons that bundle required textures (search Workshop for "CSS textures" packs), or direct clients to install the CSS content client-side.