www.makemkv.com

I thought that I'd mention this. It doesn't appear to be an actual problem though.
Disregard. I found this is the same issue as : viewtopic.php?f=7&t=32734

I'm backing up my Farscape DVDs and season 4 is giving me some unusual messages. The first disc is fine, but the other five give me a notification
about the disk possibly being created by DVDFAB or ... see attachment.

The disc is your standard store bought DVD. I borrowed one from the library to see if it was my disc and that one reported the same issue.
BTW, Mine was the 15th anniversary DVDs. The library was the 25th anniversary.

I actually had a similar issue with my copy of the first season of agents of shield it turns out i had a fake set the whole time. the way i figured it out is by checking if the disc showed up as single layer (4.7 GB) or dual layer (8.5 GB) in makemkv It could be possible that who ever sold you the set sold you a fake but it could also be possible that its just a read error

EDIT: I forgot to mention that its currently standard for tv shows to come on dual layer discs