Fix Missing Textures and ERROR Models in GMod

A pink and black checkerboard means the engine cannot find a material or its texture. A large red ERROR stands for a missing model. Usually the content only exists on the mapper's machine: it was not packed into the BSP, it comes from a game that is not mounted, such as Team Fortress 2, or it is looked up under a wrong path. Mappers fix this by packing and checking paths, players and servers by mounting or downloading the content.

What the symptoms mean

The last case has its own article: fixing cubemap reflections.

The most common causes

1. Content not packed: Custom materials, models and sounds sit in your local game folder. Hammer and your game find them there, nobody else does.
2. Content from another game: Many maps use assets from other Source games. Since the July 2025 update GMod has shipped most textures, models and sounds from Counter-Strike: Source and the Half-Life 2 episodes itself, but not their maps, music and voice-over. For other games such as Team Fortress 2 or Portal, anyone who has not installed the game and mounted it in GMod sees checkerboards and ERROR.
3. Wrong path: In a VMT, $basetexture is given relative to the materials folder and without a file extension. A model looks for its materials in the folders that were set when the model was compiled. If you move files to a different folder afterwards, those references point nowhere.
4. Incomplete files: A VMT without a matching VTF also results in a checkerboard. A model consists of several files, among them .vvd, .vtx and often .phy next to the .mdl. If one of them is missing, the model does not work.
5. Upper and lower case: Linux servers distinguish between upper and lower case letters. Write file and folder names in lower case throughout.

The fix for mappers

Everything looking right in Hammer proves nothing. The editor loads content from your local folders and from every game you have mounted.

1. Get an overview of the custom materials, models and sounds the map uses.
2. Pack these files into the BSP. Packing tools find most dependencies on their own. Still check whether the models' materials and additional textures such as normal maps are included. The details are in the article on packing custom content into a BSP.
3. Check the paths in the pakfile. Every file has to be stored there the same way as in the game folder, starting with materials/, models/ or sound/. Since December 2023, GMod has also checked embedded files against a whitelist and does not load a file that fails. The console then shows BSP embedded file failed whitelist check. The Map Scanner lists embedded Lua and asset files in the pakfile.
4. Test like a stranger. Load the BSP in a GMod installation that contains neither your addons nor your loose files, or have it tested by someone who does not have your project on their machine.
5. State required games clearly in the description. Whether you may pack third-party content into your map is a licensing question, not a technical one.

This test is a fixed part of checking a map before release. Missing content is among the first mistakes players and buyers notice.

The fix for players

• Mount the game: If you own the required game, install it through Steam. Then open the game controller icon at the bottom right of the GMod main menu, tick the game and, if the content still does not show up, restart GMod.
• Subscribe to Workshop dependencies: Many Workshop maps list required content on their page. Subscribe to that as well.
• Get the server content: If the problem only occurs on one particular server, you are missing that server's content. Many servers link a Workshop collection.

Content packs from unofficial sources are questionable both legally and in terms of security. The clean route is the mounted original game.

The fix for server owners

On a server there are two separate jobs.

The server itself needs the content. If it lacks a model, it also lacks that model's collision data. On a dedicated server you mount content from other games through the file garrysmod/cfg/mount.cfg.

The players need the content. There are three ways to get it to them:

• Content packed into the BSP arrives automatically with the map, as long as it passes GMod's whitelist for embedded files.
• Workshop content is loaded onto the server through a collection and delivered to players with resource.AddWorkshop.
• Loose files are distributed via FastDL using sv_downloadurl.

How to set this up is covered in the article on installing a GMod map on a server with FastDL and Workshop. If your map requires a mounted game, say so clearly in the server info.

FAQ

Why do I only see pink textures on some servers?

Because every server uses its own content. You are missing that server's files, or its map uses a game you have not mounted. On servers that only use standard content the problem does not occur.

Do I need Counter-Strike: Source for GMod?

In most cases not any more. Since the July 2025 update GMod has shipped most textures, models and sounds from Counter-Strike: Source itself. You still need the game installed and mounted for its original maps and for maps that use its music or voice-over.

Why does everything look right in Hammer but not in game?

Hammer and your own game find the files in your local folders. Other players do not have those folders. Only a test without your local content shows what is really inside the BSP.

What is the difference between a checkerboard and an ERROR model?

The checkerboard replaces a missing material or texture. The red ERROR replaces a missing model. If a model is visible but pink and black, the model file was found and only its materials are missing.