I've just tried. The old Backups not working, But I found a Way. I Downloaded the Themes, Plugins and Uploads Folders and the Backups from stockage/backups rename the Folder Flatboard_Pro to FlatBoard.new and Uploadet it. Rename FlatBoard to FlatBoard.old and FlatBoard.new to FlatBoard. Install FlatBoard, Upload the Backups to stockage/backups goto Forum Logout and In again, goto the AdminPanel > Backups recover the Backup. Upload The themes, plugins, Uploads Folder you Downloaded in the first step. It now should work. As last Step I created a new complete Backup, a new normal Backup and a new Archive.
Thanks, If te new Backups working with a new Install or a new Version?
I will try it out.
Thanks,