Satisfactory uses a consistent LocalAppData SaveGames root across Steam and Epic, but the account-ID directory underneath is important: a player who switched storefronts can have more than one valid subfolder. SaveEditor recommends comparing timestamps and preserving all relevant .sav generations rather than uploading or editing the first file found. This is also a format-version-sensitive game, so an external calculator saying “unsupported save version” can simply mean that tool has not caught up with a new game build.
Start with the least destructive explanation
When Satisfactory progress appears missing, first verify the active PC location: Windows: %LOCALAPPDATA%FactoryGameSavedSaveGames<account-id>. Expected files/folders: *.sav files; the filename normally reflects the save/session name, with multiple autosave/manual versions possible.. Many apparent save failures are actually profile, storefront, path-redirection, or cloud-selection problems rather than damaged game data.
Preserve every surviving copy
Back up the complete account-ID folder, not just the latest autosave. Keep several generations before moving between Early Access/Experimental/current builds or using an external calculator/editor. Before renaming, moving, replacing, or opening candidate backups, copy them outside the live directory. Do not use the only surviving file as the test specimen for repair or editing.
Check launcher and cloud state
Storefront context: Steam, Epic Games Launcher. Steam and Epic can create different account-ID subfolders under the same root. Selecting the wrong folder can make the correct .sav look missing. Cloud notes: Steam Cloud and Epic cloud are documented. Cloud conflicts are especially relevant when switching machines or branches. A sync client can reintroduce an older or newer version after a manual restore, so recovery work should keep local and cloud copies conceptually separate until the wanted progress is confirmed.
Use format and compatibility clues
Steam and Epic use the same SaveGames root but place saves in account-ID subfolders. The game format changes across builds, so external tools may lag behind the current save version. A third-party tool rejecting a .sav can mean the tool has not yet added the current Satisfactory save version; it does not prove the game file itself is corrupt. If the file exists but is ignored, compare the complete directory structure, slot/profile naming, game edition, mods/DLC, and any companion metadata. Do not assume an extension change or generic checksum tool can repair a game-specific container.
Game-specific troubleshooting
If the expected .sav is absent, look one level below SaveGames for all account-ID folders and compare timestamps. If an external parser rejects it, test the save in the game before diagnosing damage. If a known-good backup works, preserve it and create a fresh in-game save before further experiments. If no copy works, prefer read-only inspection and source-backed game-specific tooling over repeated writes.
Verification context: Reviewed against current PCGamingWiki and Official Satisfactory Wiki save-file documentation, including the account-ID subfolder and current cloud-conflict guidance.