www.makemkv.com

All six disks give the error that they appear to have been processed with DVDFab or MacTheRipper. They then rip fine without problems. I am using the official disks.

This occasionally happens - I got it with the disks from the first 5 seasons of Castle (6th was fine), purchased through Amazon. All appear to be genuine disks, but their format contains information usually only seen in previously-ripped titles.