Snapshot cannot restore: "Unknown Response"

I'm trying to restore from a source site to a destination site, coming up with this error:

An unknown response returned from Snapshot restore attempt. Aborting. Double check Snapshot settings.

I created the snapshot from the source both locally and via Google Drive, that seemed to work well.

Installed WordPress on the destination and then installed Snapshot + WPMUdev dashboard.

Imported the snapshot no problem, but cannot restore.

Origin server I don't have much access to, destination is Mediatemple gridserver.

Thank you!