Fix a Crashing GMod Server

When a Garry's Mod server keeps crashing, addons are the first suspect. Facepunch's crash page, which is written for players but applies here, lists addons right after a pointer to its support articles: if you just installed one, disable it, and otherwise bring addons back a few at a time. Find what changed, take it out, and test. This guide runs that process with the panel's tools, and ends with what to send us if the cause stays hidden.

1. Read what the Console says

Open the Console tab and scroll up from the end. The last lines before the server stopped are the ones that matter. Look for a Lua error. Facepunch's wiki shows the format: the path of the file, then the line number, then the error. A path such as addons/my_addon/lua/autorun/server/... names the addon the error came from.

If the server stopped, the power card shows Offline. Press Start to bring it back.

2. Think about what changed

Facepunch's crash guide says that if you just installed an addon, you should disable it and see whether the crashing stops. Before you do anything else, list what changed before the first crash: a new addon, a collection you changed on Steam, a new gamemode, a different map or a purchase from GmodStore.

3. Find the addon by halving

If nothing obvious changed, Facepunch suggests disabling all of your addons and then enabling them one by one or in groups.

1. In the Workshop tab, press Unlink and restart. The server stops loading its addons from the next restart. If the crashing stops, the cause is in your collection.
2. On Steam, make a new collection with half of your addons. In the Workshop tab paste its link and press Link collection. Restart and test.
3. If it crashes, the cause is in that half. If not, the other half holds it. Keep halving until one addon is left.

Facepunch also notes that it can simply be the sheer amount of addons you have installed. When no single addon is at fault, a leaner collection is the fix.

4. Check the limits

• Entities. Facepunch's wiki says a server is limited to 8192 networked entities and that ents.Create starts failing somewhere between 8064 and 8176. Past that point things stop spawning, so a server filled with props or NPCs is worth checking. You can read the current count in the Console with lua_run print(ents.GetEdictCount()). Our test server printed 130 on an empty Sandbox map.
• Memory. Under the console in the Console tab, the live graphs show RAM use. Compare it with the RAM your plan has. The table in GMod server: connect, Workshop, gamemodes shows what Sandbox, TTT and DarkRP servers tend to need.

5. Rule out a game update

Facepunch's crash guide says a crash can be down to a Garry's Mod update, and that the best thing to do then is report it to the developers. Restart the server first, so it is on the latest version. How to update your GMod server explains the Updates setting and what to do if an update stalls. If it still crashes on the latest version with no addons, report it on Facepunch's bug tracker, after reading the page's readme.

6. Keep Lua refresh off

In the Startup tab, the Server card has Lua refresh. The panel recommends Off on a dedicated server. Facepunch's wiki says Auto Refresh runs a whole Lua file again whenever it changes on disk, and that this can cause issues when global data is overwritten.

If you still can't find it

Open a support ticket with the lines from the Console leading up to the crash, the time it happened and your collection link. Facepunch's crash page asks anyone reporting a crash what they were doing when it happened and whether they can make it crash again. For a crash on startup it also asks whether it crashes without any addons and on every map. The answers help us too.