How to Fix Barotrauma Campaign Sync Issues
Diagnose and fix campaign desync — players stuck on loading screens, rolled-back progress, wrong submarine location, or crew members out of sync.
What Campaign Desync Looks Like
Campaign desync shows up as:
- Players stuck indefinitely on the loading screen when joining
- Crew members appearing in wrong locations or missing from the roster
- The submarine showing at an outpost the crew didn't travel to
- Mission progress or money rolled back to a previous session
- The server refusing to load the campaign save at all
Most desync issues come from one of five root causes. Work through them in order.
1. Version Mismatch
All players must run the exact same game version as the server. Even a minor patch difference can cause loading failures.
Fix: have every player verify game files via Steam:
- Right-click Barotrauma in Steam → Properties → Local Files → Verify integrity of game files
Check the server version by looking at the console output on startup. Compare to client versions shown in the game's main menu.
2. Mod Mismatch
One or more players have a different mod version, extra mods enabled, or mods in a different load order than the server.
Fix:
- Have the server host share the exact mod list (Workshop IDs and order)
- All players unsubscribe from mods not on the list
- Enable mods in the same order as the server via the in-game mod manager
- Have everyone fully exit and relaunch before reconnecting
3. Corrupted Save State
If gamesession.xml is corrupted — from a crash, bad write, or format change after an update — the campaign won't load or will load into a broken state.
Fix:
- Stop the server
- Check
Servers/<ServerName>/Saves/<CampaignName>/gamesession.xmlfor XML errors (open in a text editor, look for unclosed tags) - Look for
.bakfiles in the same folder and try replacinggamesession.xmlwith the.bakcopy - If neither works, restore from a manual backup — see How to Back Up Your Barotrauma Server
4. Server Crash Mid-Round
If the server crashes during an active round before the autosave triggers, the round's progress is lost. The campaign state reverts to the last outpost visit or round end.
This is expected behavior — it's not true desync, just lost progress. Rejoin the server and start the last round over.
5. Client Joining During an Active Round
Barotrauma does not support players joining mid-round in campaign mode. A client who connects while a round is in progress will sit in limbo until the round ends and the crew returns to the submarine.
Wait for the round to complete, then have the player join from the main menu.
After Fixing
After resolving any of the above: have all players fully disconnect and close the game, then rejoin fresh. Partial reconnects can perpetuate desync even after the root cause is fixed.