Saved World Will Not Load Fix

If your Moon Sweepers saved world will not load, update the game to version 1.0.3 or later before you try anything else. The 1.0.3 patch, released on October 24, 2026, specifically fixed large, heavily cleaned bases that looked corrupted and refused to load even though their save files were intact. The same patch added automatic save repair from a backup or a recent snapshot.

Three conditions change what you should do next:

• Solo world still fails after updating: copy the whole save folder somewhere safe, then work through Steam Cloud and file checks.
• Co-op world fails or you cannot join: every crewmate must run the same version. The developers state that all crewmates must be on version 1.0.3 to play together.
• The game reports a repair: the world loaded from a backup or snapshot, so check how much recent progress came back with it.

The key limitation is that the repair system relies on an earlier saved state. It is not a promise that every damaged world can be fully restored, and the developers still list crashes as ongoing work.

What Patch 1.0.3 Changed for Saves

The developers described the launch save problems in their October 24 message: some worlds failed to load, and save protection needed work. The 1.0.3 patch notes split this into two separate fixes.

If your world stopped loading before October 24, try it again after the update. The patch notes say the large worlds that looked corrupted were never broken on disk, which means the safest first step is to change nothing in the save folder and simply update.

Quick Fix Order

Work through these steps in order. Stop as soon as the world loads.

1. Close the game fully. Exit to the desktop rather than only returning to the main menu.
2. Confirm the version. Let Steam finish downloading any pending update for Moon Sweepers. The public build and the preview branches can differ, so check which version you are on.
3. Back up the save folder. Copy it before any further troubleshooting, as described in the next section.
4. Launch and load the world once. Wait longer than usual if the base is large; big worlds were the ones affected at launch.
5. Read any repair message. If the game repaired the save, play a few minutes and confirm your buildings, vehicles and money look right.
6. Check Steam Cloud. If Steam reports a sync conflict, pick the copy that matches your most recent session, using your backup as insurance.
7. Verify the game files in Steam. This checks the installed game, not your world, and rules out a damaged install.
8. Report it. If the world still fails, report it to the developers with the details listed at the end of this guide.

Back Up the Save Folder First

Steam's cloud-save configuration for Moon Sweepers points to this folder on Windows:

%USERPROFILE%\AppData\LocalLow\DragDropGames\MoonSweepers\MoonSessions

That is the folder Steam Cloud watches for the game, and it syncs every file inside it. Treat it as the home of your worlds.

To make a backup:

1. Close Moon Sweepers completely.
2. Open File Explorer and paste the path above into the address bar. Windows expands %USERPROFILE% to your own user folder.
3. Copy the entire MoonSessions folder, not individual files.
4. Paste the copy somewhere outside the AppData folder, such as a dated folder on another drive.
5. Repeat before every major troubleshooting step and before any big update.

The AppData folder is hidden by default, which is why pasting the full path is easier than browsing to it.

What not to do with save files

• Do not rename or edit files inside MoonSessions. The file format is not documented, and the game now runs its own checks and repairs when loading.
• Do not delete the folder to reset the game unless you already have a separate copy you trust.
• Do not restore an old copy while Steam is syncing. Wait until Steam has finished, close the game, then restore.
• Do not mix folders between computers by hand unless the game is closed on both machines.

The 1.0.3 repair system expects to find its own backup and snapshot data alongside your world. Leaving the folder intact gives it the best chance of working.

Large, Heavily Cleaned Bases

At launch, the most common version of this problem hit players who had already cleaned a lot of ground and built a sizeable base. The world appeared corrupted and would not load properly.

The developers later confirmed that those save files were fine. The fault was in loading such a large world, and patch 1.0.3 fixed it. If this matches your situation:

• Update to 1.0.3 or later and load the world again without touching any files.
• Give a big base extra time on the loading screen.
• If loading is very slow, note it when you report the issue. The same patch also improved performance on big bases and reduced stutter while terrain loads.

This is also why restoring an older backup is usually the wrong first move for a big base. An older copy is just as large, and it throws away progress the current save still contains.

When the Game Repairs a Save

Since 1.0.3, a damaged save is repaired automatically as it loads. The game uses either the save's backup or a recent snapshot, and shows a message when a repair was needed.

After a repair message:

1. Do not immediately start a long session. First compare the world to what you remember.
2. Check your money, recent purchases, newly placed buildings and recently cleaned sectors on the Moon Map.
3. If recent work is missing, the repair most likely came from an earlier snapshot. That progress is not recoverable from inside the game.
4. Make a fresh copy of the MoonSessions folder once you are satisfied the repaired world is playable.

If no message appears and the world still fails, the automatic repair did not resolve it. Keep your backup and move on to Steam Cloud and file checks.

Steam Cloud Conflicts and Switching PCs

Moon Sweepers lists Steam Cloud support on its store page, and the cloud configuration covers the MoonSessions folder. Cloud sync is useful, but a conflict can make a working world look broken.

Common situations:

• You played on two computers. Steam may ask which copy to keep. Choose the one from the machine you played on most recently, and keep a manual backup before choosing.
• You played while offline. Reconnect, launch Steam and let it upload before playing on another PC.
• A newer copy downloads but seems older. Close the game, check the timestamps on your manual backup, and compare progress before overwriting anything.

Steam Cloud keeps your files in sync between machines. It is not an archive of every older version, so your own dated copies are the real safety net.

Multiplayer Worlds and Version Mismatch

The 1.0.3 patch notes end with a direct warning: all crewmates must be on version 1.0.3 to play together. A crew where one player is on a different build can fail to connect, which is easy to mistake for a broken world.

To rule this out:

1. Ask every crewmate to fully restart Steam so the latest update downloads.
2. Check whether anyone has opted into a preview branch. Steam's branch list for the game included a public build, a Version 1.0.1 branch and preview branches for 1.0.3 and 1.0.4 around October 25. Anyone on a different branch can end up on a different version from the rest of the crew.
3. Have everyone return to the same branch, usually the public build, unless the host deliberately runs a preview and everyone matches it.
4. Load the world on the host's PC first. The crew joins the host's save, so a failure there affects everyone.

Two other 1.0.3 changes can affect an older co-op world:

• The crew now uses the host's upgrade matrix. Older saves keep the highest upgrade level anyone had bought, so the world can look different after the update without being damaged.
• Hosts can kick or ban players from ESC > Your Crew. A banned player cannot join that save again until the host unbans them there. If one specific person cannot join while everyone else can, check this list.

Reporting a World That Still Will Not Load

The developers are a two-person team and have asked players to report bugs in their official Discord community, which is linked from the Steam store page. The Steam community discussions are the other public channel.

Include these details so the report is useful:

• Your game version and whether you are on the public build or a preview branch.
• Whether the world is solo or co-op, and whether you are the host.
• Roughly how large the base is and how much of the Moon you had cleaned.
• Whether a repair message appeared.
• Whether the problem started after a crash, an update or switching computers.
• Whether Steam showed a cloud conflict.

Keep your untouched backup of the MoonSessions folder until the issue is resolved. If a later patch fixes another loading case, that copy may be what brings your world back.

Prevent It From Happening Again

A few habits make a future load failure much less painful:

• Back up after big milestones. A new garage, a production line or a large cleared region is worth a dated copy.
• Close the game normally. Avoid ending the process during saving, and let Steam finish syncing before shutting down the PC.
• Update the whole crew together. Agree on one branch and update before each session.
• Keep several copies. One recent backup plus one older backup protects you if the newest copy turns out to be damaged too.

The patch notes do not state how often the game creates its own backups or snapshots, so do not rely on them alone. Your own copies are the only backups you fully control.