Snapshots not importing

I’m trying to set up a development environment for my website. I was using the Snapshot tool to backup everything from my live environment to the new dev environment. I made a snapshot with my live site but can’t seem to import it into my new site. I’ve tried uploading it to the dev site directory, hitting it on the live server, just refreshing the snapshots – but I keep getting the same error – “Error: Manifest data not found in archive.” Any ideas what’s going on that’s keeping me from moving this site over?