007 First Light Save Data Corrupt Cloud Sync Error PC Fix

What is the 007 First Light Save Corruption / Cloud Sync Error?

After several hours of progress, 007 First Light players are seeing one of two related failures: a Steam Cloud sync conflict dialog ("There is a conflict between the data in the Steam Cloud and on this computer") or a silent main-menu state where mission progress, gadget unlocks, and skill points have rolled back hours. The game writes saves to %LOCALAPPDATA%\IOI\007FirstLight\Saved\SaveGames\ and uploads through Steam Cloud, but IOI's save versioning has been mismatching the cloud copy since the early-access patch shipped in late May 2026. The good news: the local file is almost always intact, and you can force the local copy to win the conflict.

When does it occur?

• Quitting on one PC and resuming on another (Steam Deck → desktop)
• After a Steam crash that left the upload mid-flight
• Following the May 2026 patch (build 1.0.4.x) that changed the save schema
• After alt-tabbing during an auto-save checkpoint
• When OneDrive or another sync client is also watching %LOCALAPPDATA%
• After a Windows update reboot triggered mid-mission

Common causes

• Steam Cloud upload was interrupted mid-write and the manifest is now ahead of the file
• A second device wrote a newer save that overwrites your local progress
• Antivirus quarantined Save_Slot_0.sav mid-write, leaving a 0-byte file
• The save header version is from build 1.0.3 but you're now on 1.0.4
• OneDrive Known Folder Move silently redirected %LOCALAPPDATA%
• Disk free space dropped under 1 GB during the auto-save flush
• Manual edits to the save file via a save editor corrupted the checksum

Step-by-step fixes

1. STOP the game immediately and do not click "Use cloud" yet. Closing Steam without picking a side leaves both copies intact. The wrong choice here is what destroys progress permanently.
2. Back up everything first. Open File Explorer to %LOCALAPPDATA%\IOI\007FirstLight\Saved\SaveGames\ and copy the entire folder to your Desktop. Then copy %PROGRAMFILES(X86)%\Steam\userdata\<your-steamid>\<007-app-id>\remote\ too — that's the Steam Cloud staging copy.
3. Resolve the Steam Cloud conflict in favor of local. Reopen Steam. When the conflict dialog reappears, click "Upload to the Steam Cloud" — this pushes your *local* file up and discards the broken cloud version. (Counter-intuitive: "Use cloud" downloads the broken version.)
4. If you already picked "Use cloud" and lost progress, close Steam fully (taskkill /F /IM steam.exe), restore your SaveGames folder from the Desktop backup, then disable Steam Cloud for the game (right-click in Library > Properties > General > uncheck "Keep saves in the Steam Cloud") and relaunch — the local copy will now load.
5. Repair a 0-byte or corrupted slot. Look for Save_Slot_0.sav, Save_Slot_1.sav, Save_Slot_2.sav. If the active slot is 0 bytes or won't load, rename one of the auto-save backups (AutoSave_*.sav) to overwrite it. IOI writes 3 rolling auto-saves; check timestamps to find the newest valid one.
6. Force a clean schema migration. If the save loads but progress is rolled back, on build 1.0.4+ launch the game with the -skipsavemigration flag via Steam launch options. The game re-imports the legacy save into the new schema in-place.
7. Stop OneDrive from redirecting AppData. Right-click the OneDrive icon > Settings > Backup > Manage backup, uncheck *Documents* and confirm that %LOCALAPPDATA% is not being mirrored. Move your save folder back to true local AppData if it was redirected.
8. Whitelist the save folder in your antivirus. Add %LOCALAPPDATA%\IOI\007FirstLight\ as a Controlled Folder Access exclusion (Windows Security > Virus & threat protection > Manage ransomware protection) so future writes are never quarantined.

If it still doesn't work

If neither local nor cloud has a recoverable save, check %LOCALAPPDATA%\IOI\007FirstLight\Saved\Crashes\ — IOI ships an emergency snapshot writer that dumps a RecoverySave.bak after a hard crash. Rename it Save_Slot_0.sav and place it in the SaveGames folder. If that's empty too, your only option is IOI Support (support.ioi.dk) — attach the Saved\Logs\007FirstLight.log, your Steam ID, and an approximate timestamp of your last known good play session; they have restored cloud snapshots for documented sync-bug victims. Cross-check our [007 First Light crash guide](/en/errors/007-first-light-crash-wont-launch-pc) and the [Online Fix comprehensive guide](/en/errors/007-first-light-online-fix-comprehensive-guide) if the corruption was triggered by a launch crash. Recurring dreams of losing things you can't replace? Our [losing-phone dream guide](https://dreams.decodesignals.com/en/dreams/losing-phone) explains why the brain replays loss.