www.makemkv.com

If MakeMKV says "No disc", that's what the operating system told it. Either the drive (most likely) or Windows could not detect a formatted disk in the drive. This error will show up for UHD disk in a BD-only drive, for example.

Did other UHD discs inserted AFTER these two get recognized?

I have the same issue with 2 separate disks so far.

Inception (the new UDH steelbook from zavvi)
Leon (again Vavvi directors cut UHD)

All other 4k disks have no issues whatsoever just this 2 new ones are not being detected at all. I realize this is not necessarily a MakeMKV issue but if anyone has any way to solve this it would be great.