Troubleshooting & messages · Free space and clean-up messages
What does "Backup status couldn't be determined" mean when deleting a snapshot?
Short answer: Storage Studio can't tell whether this snapshot already reached Time Machine. Deleting it frees space but may lose that state for good — run a Time Machine backup first, or leave it.
Storage Studio couldn't tell whether this snapshot's contents have already reached your Time Machine backup. Deleting it will reclaim the space, but if Time Machine hasn't backed up since it was taken, the state it holds is lost — and that can't be undone.
The safe route: connect your Time Machine drive, let a backup finish, then come back. Or leave the snapshot alone; macOS removes it on its own over time.