[Guide] Missing Map, Map Differs from Server, & Couldn't CRC Map Error(s)

[The Guy]

Garry's Mod's Fast DL is quite unreliable and can vary client to client, due to different operating systems and configurations. Unfortunately, this causes some clients to 'miss' or receive incomplete or corrupted downloads, and often sometimes cause rare errors that will say something alone the lines of 'Missing map, disconnecting', 'Map Differs from Server' and or 'Couldnt CRC Map', and will kick you off of the server when you are trying to download our content. This is an intermittent Garry's Mod issue and not something we can fix ourselves. However, there are a few methods you can try to correct these issues:

Spoiler: Missing Map

Option 1 for 'Missing Map':

> Close your Garry's Mod.

> Reopen your Garry's Mod.

> Join the server.

Sometimes, this issue can be easily corrected simply by completely closing your Garry's Mod and relaunching, then rejoining the server. For some reason, map files sometimes simply refuse to download the first time you join the server, but will the next time the client reopens their Garry's Mod.

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Option 2 for 'Missing Map':

> Close your Garry's Mod.

> Go to this directory on your PC: C:\Program Files (x86)\Steam\steamapps\common\GarrysMod\garrysmod\download\maps\

> Download the map that is missing from our webserver:

• firelink_medieval
  
  
• sbs_forgotten_school
  
  
• sbs_forgotten_school_night
  

> Open the .bz2 file, and extract the .bsp file from the bz2 file. Drag the raw .bsp file into the directory mentioned above.

> Then, open your Gmod, reconnect, and you should have no further issues.

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Option 3 for 'Missing Map':

If the above does not work then you can do this:

> Close your Garry's Mod.

> Go to this directory on your PC: C:\Program Files (x86)\Steam\steamapps\common\GarrysMod\garrysmod

> Inside there, delete the four folders named "cache, download, downloads, and downloadlist"

> Then, open your Gmod and reconnect to redownload everything.

If you are still having issues, MAKE SURE you are NOT joining the server in offline mode on steam, as that causes issues with downloading things. Lastly, if none of this works, it is likely a network/computer configuration error or issue on your end which unfortunately I cannot help you with.

Spoiler: Map Differs From Server

Option 1 for 'Map differs from Server':

> Close your Garry's Mod.

> Go to this directory on your PC: C:\Program Files (x86)\Steam\steamapps\common\GarrysMod\garrysmod\download\maps

> Delete the .bsp (map file) that is giving you this error.

> Reopen Garry's Mod, rejoin the server, download a fresh version of the map file.

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Option 2 for 'Map differs from Server':

> Close your Garry's Mod.

> Go to this directory on your PC: C:\Program Files (x86)\Steam\steamapps\common\GarrysMod\garrysmod\download\maps\

> Delete the .bsp (map file) that is giving you this error.

> Download the same map file from our webserver:

• firelink_medieval
  
  
• sbs_forgotten_school
  
  
• sbs_forgotten_school_night
  

> Open the .bz2 file, and extract the .bsp file from the bz2 file. Drag the raw .bsp file into the directory mentioned above.

> Then, open your Gmod, reconnect, and you should have no further issues.

---

Option 3 for 'Map differs from Server':

If the above does not work then you can do this:

> Close your Garry's Mod.

> Go to this directory on your PC: C:\Program Files (x86)\Steam\steamapps\common\GarrysMod\garrysmod

> Inside there, delete the four folders named "cache, download, downloads, and downloadlist"

> Then, open your Gmod and reconnect to redownload everything.

Spoiler: Couldnt CRC Map

Option 1 for 'Couldn't CRC Map':

> Close your Garry's Mod.

> Go to this directory on your PC: C:\Program Files (x86)\Steam\steamapps\common\GarrysMod\garrysmod\download\maps

> Delete the .bsp (map file) that's giving you this error.

> Reopen Garry's Mod, rejoin the server, download a fresh version of the map file.

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Option 2 for 'Couldn't CRC Map':

If you are still getting this error then you can do this:

> Close your Garry's Mod.

> Go to this directory on your PC: C:\Program Files (x86)\Steam\steamapps\common\GarrysMod\garrysmod\download\maps\

> Delete the .bsp file (map file) that is giving you this error.

> Download a fresh version of the same map manually from our webserver:

• firelink_medieval
  
  
• sbs_forgotten_school
  
  
• sbs_forgotten_school_night
  

> Open the .bz2 file, and extract the .bsp file from the bz2 file. Drag the raw .bsp file into the directory mentioned above.

> Then, open your Gmod, reconnect, and you should have no further issues.

This error occurs when you have an 'incomplete' or 'corrupted' download of a map file.

PS: These techniques will work on all Garry's Mod servers. If you still get these kinds of errors when joining a server after doing this, that either means A: The server does not have their Fast DL or Workshop DL configured correctly or B: You are having a network/computer/game configuration issue depending on your operating system, and it's noteworthy to know Gmod does not tend to work well with MAC and newer versions of Windows.