Troubleshooting & messages · Undo, move back and Recycle Vault
Why does Storage Studio say a folder isn't on this Mac any more?
Short answer: The item disappeared — removed or renamed by you or another app — before Storage Studio acted. Refresh the window for an up-to-date list.
The item was in Storage Studio's list, but by the time you acted on it, it had gone — another app, a sync service or you removed or renamed it. Storage Studio doesn't recreate things it didn't remove, so it simply tells you.
Refresh the window to get an up-to-date list.