The Sims 4 already keeps several recovery generations next to each main slot, which makes indiscriminate cleanup a mistake. A good backup preserves the whole saves directory, including `.save.ver0` through `.ver4` files. If a slot becomes unusable, duplicate the directory first and test recovery on the copy. Also remember that the Documents tree may be redirected or synchronized by OneDrive, so the file you replace locally may not be the only copy involved.
Start with the least destructive explanation
When The Sims 4 progress appears missing, first verify the active PC location: Windows: %USERPROFILE%DocumentsElectronic ArtsThe Sims 4saves | macOS: $HOME/Documents/Electronic Arts/The Sims 4/saves/ | Linux / Steam Play: Steam Play: <SteamLibrary-folder>/steamapps/compatdata/1222670/pfx/. Expected files/folders: Slot_*.save
Slot_*.save.ver0 … .ver4. Many apparent save failures are actually profile, storefront, path-redirection, or cloud-selection problems rather than damaged game data.
Preserve every surviving copy
Copy the complete saves directory so each main slot and its .ver0-.ver4 recovery generations remain together. 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: EA app, Steam, Epic Games Launcher. The active Windows saves still live under Documents/Electronic Arts. Steam and Epic launch through EA services but should not be assumed to maintain a separate independent save directory. Cloud notes: OneDrive Documents backup can synchronize or redirect the saves directory when enabled. Treat that as a second copy source when diagnosing unexpected restores. 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
The game maintains main Slot_*.save files and several rotating .save.verN recovery copies. These historical versions are valuable rollback points and should be preserved before manual recovery. The save can depend on installed packs, custom content, and mods. Missing content after migration is not the same as binary save corruption. 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 a main Slot file fails, preserve it first, then work from a copied .save.verN generation. Do not rename over every version until one recovery copy has been tested. 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: Windows/macOS/Steam Play save paths and storefront/OneDrive context were reviewed against current PCGamingWiki coverage. Rotating Slot recovery filenames follow the standard Sims 4 desktop layout.