When a restore fails it can wipe out the root site collection that you specified. If you don't have a backup of that site collection, it's gone.
There is a trick to moving content databases (which content site collections) You can create a site collection using a temporary content database. If you then delete the temporary content database then attached a copy of a content database from another Sharepoint site, if Sharepoint can match the site collection names it will reconnect them.
However, the same thing that is blocking the restore will block you from doing that. You can't move a newer schema to an installation with an older schema.
Just to be clear, this is a list you need to move not a site collection?