I have a My Book Live that has been in place for over 2 years. When I installed the drive originally I created multiple shares; one of which is called backup.
I recently applied the latest firmware and now I am unable to get back to my ‘backup’ share since it is now a restricted share.
I figured out what to do. I used SSH to move (mv) my files from the ‘now restricted’ backup share to a new one I called storage. Please do not restrict this name in the future!