Snapshot Pro "Error: Manifest data not found in archive."

I am getting this error when trying to upload a snapshot from my original wordpress site.

I have already tried directly downloading and uploading the file via FTP (as I have read other support tickets suggest). I have tried uploading it both to the default snapshot directory, and uploading it to a custom (/public_html/snapshots/) directory and telling snapshot where I put it. I have tried my 2 most recent snapshot backups with the same error message.