Match this symptom
A copied Steam world exists on disk, but the dedicated server loads an empty Cascade or generates another world with no expected bases, inventories, or progression.
The answer first
Stop before the fresh world saves repeatedly. Preserve both folders, copy the complete Steam source world under Saved/SaveGames/Server/Worlds, then either name that folder Cascade or set -WorldSaveName to its exact folder name.
Confirm the source is supported
The official migration guide supports a Steam local/player-hosted world under the Steam user's SaveGames path. It explicitly does not support local worlds from PlayStation 5, Xbox, or Windows Game Pass/Store. Crossplay joining does not change that file-format boundary.
Preserve source and accidental destination worlds
- 1Stop the dedicated process and the source player-hosted session.
- 2Copy the Steam source world from %LocalAppData%/AbioticFactor/Saved/SaveGames/<SteamID>/Worlds/<world> to a protected staging folder.
- 3Quarantine the newly generated Server/Worlds/Cascade rather than deleting it.
- 4Record the current -WorldSaveName and -SandboxIniPath arguments.
Place and select the complete world
- 1Copy the intact world folder under AbioticFactor/Saved/SaveGames/Server/Worlds.
- 2Choose one identity method: rename that folder to Cascade, or preserve its name and set -WorldSaveName=<exact folder name>.
- 3Check that a manager or Windows service is not overwriting the launch argument on startup.
- 4Keep its per-world SandboxSettings.ini with the same world unless an explicit -SandboxIniPath selects another file.
Validate a migration beyond first join
Start privately, verify a recognizable base, player data, progression, and sandbox behavior. Use Player Management's Force World Save, close normally, restart, and verify again. The second load confirms the server did not merely show cached or transient state.
When the source is a console or Game Pass save
Do not run converters against the only copy or imply that an unsupported source is a routine import. Preserve it, start a fresh dedicated world, and watch the official migration guide for a future supported path.
Verify that the folder is a complete Steam world
Before moving it again, compare the staged folder with the original Steam Worlds directory rather than assuming the first nested folder is the world root. Provider ZIPs often add an outer archive directory. A misplaced extra level can leave the files intact but invisible to the server because Server/Worlds contains a container instead of the world selected by -WorldSaveName.
Keep the imported world's own sandbox file and capture a directory listing with sizes and timestamps. After the private save/restart test, compare the files that changed: writes should occur inside the selected imported world, not a second Cascade elsewhere. If writes land in another folder, stop and correct WorldSaveName or the service launch definition before inviting players; copying new files back into the old world would mix two timelines.