Mass Account Transfer Fails (set archive failed, Backup provided was empty)

I'm attempting to transfer my accounts from an old VPS to my new server without any luck. All of the accounts, not matter how big or small, fail to import due to the following error (obviously with various filenames):

The one thing that sticks out at me is the file extension ("..tgz" instead of ".tgz"). Has anyone else run into this?

Thank you,
Chris