Skyrim Special Edition backups should include mod context, not just bytes. The base .ess file is the core save, but SKSE installations can add a matching .skse cosave and the save can reference plugins that are no longer installed. That means a technically intact file may still fail or behave differently on another setup. SaveEditor.com therefore treats the save file, its optional cosave, and the mod/load-order context as separate pieces of compatibility evidence.
Which storefront context matters
Documented The Elder Scrolls V: Skyrim Special Edition PC launchers/storefronts: Steam, GOG Galaxy, Epic Games Launcher, Microsoft Store / Xbox app. Steam and GOG use differently named Documents folders. Microsoft Store packaging differs and should not be treated as the same path simply because the game title is identical. The active storefront/account should be identified before any restore because cloud and local storage may not use the same path or container across editions.
Documented cloud behavior
Steam Cloud, GOG Galaxy, Epic/Xbox cloud support, and optional OneDrive Documents backup can all affect which copy is restored. Cloud synchronization is useful for continuity, but it can also turn a restore into a conflict-resolution event. Let synchronization settle before making a manual backup, and keep an offline copy outside any folder monitored by the launcher or operating-system sync service.
Local save roots still matter
The researched local save boundary is Windows: Steam: %USERPROFILE%DocumentsMy GamesSkyrim Special EditionSaves
GOG: %USERPROFILE%DocumentsMy GamesSkyrim Special Edition GOGSaves | Linux / Steam Play: Steam Play: <SteamLibrary-folder>/steamapps/compatdata/489830/pfx/; the known file or folder pattern is *.ess
*.skse (when created by SKSE). A cloud-enabled game still has concrete local data involved in ordinary play, and that local context is what you need when identifying which copy was modified most recently.
Avoid accidental overwrite loops
For an unmodded setup, back up the complete Saves folder. For SKSE/modded play, preserve matching .ess and .skse files plus a record of the mod list/load order. When restoring, close the game and launcher, preserve both the current local copy and the backup you want to test, then place the intended data in the matching profile/storefront location. Do not repeatedly open the game between different copies without noting which side the cloud client selected.
Compatibility and conflict checks
Original Skyrim saves can sometimes be used by Special Edition, but modded saves may fail when required plugins are missing or incompatible. If progress disappears or rolls back, When a save fails after moving PCs, check the mod/plugin environment before assuming the .ess itself is corrupt. OneDrive can also redirect or synchronize the Documents folder unexpectedly. Resolve identity/path/cloud questions first. A cloud conflict is not proof that the save itself is corrupt, and a successful upload is not proof that files from another storefront are compatible.
Verification context: Steam/GOG save paths, original-to-Special-Edition compatibility note, cloud support, and Steam Play behavior were reviewed against current PCGamingWiki coverage.