Snapshot Import Error

I'm trying to import a snapshot backup from to this website,, for development purposes. I've followed the instructions on this page, but when I do the import, I get an error:

ERROR: Unable to locate table restore file from archive: (*DB prefix redacted for security reasons on this support ticket*)_options.sql

This is a straightforward backup of all files, DB entries, plugins, media, etc, but the import doesn't work.