Barotrauma Server Troubleshooting

This guide covers the most common Barotrauma server issues and how to fix them.

Required Ports

Barotrauma requires two UDP ports to be open:

On XGamingServer, these are handled automatically. If you're running a self-hosted server, make sure both are open inbound on your firewall.

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Server Not Appearing in Browser

Symptoms: The server doesn't show up in the in-game server list.

Fixes:

• Confirm public="true" in serversettings.xml
• Wait 2–5 minutes — it takes time to appear in Steam's master server list
• Use Direct Connect as a workaround: in the Barotrauma client, click Join Server → Direct → enter IP:port
• Verify UDP port 27016 is open (needed for Steam browser queries)

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"Steam Authentication Failed"

Symptoms: Players see an auth error when trying to connect.

Causes & fixes:

• Port 27016 is blocked — Steam uses this port to validate player tickets
• Version mismatch — make sure your server and all clients are on the same game version
• For private/LAN use only, you can bypass this by setting RequireAuthentication="False" in serversettings.xml (not recommended for public servers)

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Changes to serversettings.xml Not Saving

Symptom: You edit serversettings.xml but settings revert after restart.

Cause: The server overwrites serversettings.xml when it shuts down.

Fix: Always stop the server before editing the file, not after.

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Mods Not Loading

Symptoms: Mods don't appear to be active, or the server console shows errors.

Fixes:

• Verify the path in config_player.xml exactly matches the folder name in LocalMods/ — it's case-sensitive
• Check Logs/ in the server root for specific error messages
• For older mods: open filelist.xml inside the mod folder and change any Mods/ path references to LocalMods/
• Make sure you stopped the server before editing config_player.xml

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Players Can't Connect After Adding Mods

Cause: Mod mismatch — players need the same mods installed as the server.

Fix: Have players subscribe to the same Workshop mods. Barotrauma will tell them which mods are required when they attempt to join.

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Server Crashes on Startup

Check the console output for the first error line. Common causes:

• A mod has a broken filelist.xml — remove recently added mods and test
• serversettings.xml has a syntax error — check for malformed XML
• The submarine name in serversettings.xml doesn't match any file in Submarines/ — verify capitalization

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High Ping / Lag

Fixes:

• Lower the tickrate value in serversettings.xml (default 20 — try 15 for weaker connections)
• Reduce MaxPlayers if the server is underpowered for the current player count
• Reduce the number of active mods — complex mods increase server load

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Campaign Save Not Loading

Symptoms: The save doesn't appear in the campaign lobby, or loading fails.

Fixes:

• Both files must be present: [SaveName].save and [SaveName]_CharacterData.xml
• Verify both files are in Saves/Multiplayer/ on the server
• Make sure you stopped the server before uploading save files — uploading while the server is running can cause corruption

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Players Spawning as Wrong Job / No Job

Cause: Job slot limits per submarine — some submarines cap specific jobs.

Fix: Each submarine has job slot limits (e.g. only 1 Captain). If too many players pick the same job, some will be moved. Set SubSelectionMode="Manual" and pick an appropriate submarine for your crew size.

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Admin Commands Not Working

Symptoms: Console commands return permission errors.

Fixes:

• Verify the player's entry in Data/clientpermissions.xml — check the SteamID64 is correct
• Confirm the preset or permissions value includes ConsoleCommands
• Run clientlist to check what permissions are actually assigned to connected players

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Related Guides

• Configure Your Server
• Install Mods
• Adding Admins
• Console Commands