Troubleshooting & Fixes

1. Verify your build. Open Steam and make sure Moon Sweepers is not waiting on an update. Two patches shipped in two days; if you are on anything older than v1.0.4, update before doing anything else.
2. Check your crew's versions too — mismatched builds block co-op entirely.
3. Restart once. Several save fixes — including crash recovery — only run when the game starts.
4. If you use unofficial mods, disable them. Patches can silently break unsupported mods, and the developers do not support them.

If you are still seeing any of the following, you are almost certainly not on v1.0.4 yet. All of these were listed in official patch notes:

v1.0.4 made DirectX 11 the default renderer specifically to prevent crashes on AMD GPUs. This is the single change most likely to fix a hard crash on launch or during play.

• The game now starts in DirectX 11 unless you override it.
• If you previously added `-force-d3d12` to your Steam launch options, remove it and let the game run its default.
• If you genuinely want DirectX 12, add `-force-d3d12` back deliberately — and remove it again if crashes return.

There is no native Linux build — the game runs on Steam Deck through Proton. v1.0.4 fixed startup problems that occurred with older Proton versions, so if it refuses to launch on Deck, force a newer Proton compatibility layer before assuming anything else is wrong.

The save system was reworked across both patches, and this is where most players lose sleep unnecessarily:

• Automatic backups — each save slot now keeps up to 5 full backups, taken one minute into every session and then every 30 minutes.
• They live outside Steam Cloud — at `C:\Users\[user-name]\AppData\LocalLow\DragDropGames\MoonSweepers\Backups`. Steam will not restore them for you on a new machine, so copy them manually before reinstalling Windows or swapping hardware.
• Automatic repair — if a save or part of it is damaged, the game restores it from your backups when the world loads and tells you it happened.
• Crash recovery — after a crash, the game checks your save files on the next start and repairs damaged ones.
• Much faster saves — large, heavily cleaned bases now save in "a fraction of a second instead of up to half a minute," and quitting no longer hangs on "Saving your progress…".

• Everyone must be on the same version. This has been enforced since v1.0.3. Update all clients, then try again — partial updates are the usual cause.
• Upgrades follow the host. Since v1.0.3 the crew shares the host's upgrade matrix, so missing upgrades are not a bug — see Co-op & Crew.
• Unclean ground that keeps reappearing was fixed in v1.0.4 by reworking ground synchronisation. Update everyone, not just yourself.

The developers continue to list these areas of work in their own posts. If you are seeing one of them, it is a known focus rather than a mystery:

• Crashes — reduced substantially, not declared eliminated.
• Production systems — behaviour of machines and conveyors at scale.
• Automation reliability — greatly improved by the v1.0.4 J.O.O.N.A.S. rework but still under work.
• Progression balance — explicitly acknowledged as unresolved.

The v1.0.4 patch notes close with a direct request: report bugs in their Discord so the two-person team can fix them quickly. Use https://discord.gg/5ATRkXkAAe (linked from the Steam store page).

• Your build number — check it before writing the report; the issue may already be fixed
• Whether it happens in single-player, co-op, or both
• Whether anyone else in your crew can reproduce it
• Your GPU model, and whether you are forcing `-force-d3d12`
• Whether it started before or after a particular patch