This is why we clean new UHD discs. :)

[scorp508]

This brand-new disc shrink-wrapped from Amazon made me a firm believer in the need to clean UHDs before ripping. Just look at the layer of whatever it is all over the inside of the case. I tried ripping before cleaning and errored every time. After a little Dawn dish soap, it ripped perfect on the next try. It isn't shown, but even the data side of the disk was patchy with whatever that substance is. The 1080p Blu-Ray ripped fine without cleaning.

[golobulus]

I too have received discs like this and I have had the same experience. Amazing that the players can cut through this stuff.