This was known about HDDVDs a few years back too. I pulled my Harry Potter collection out for my kids and their friends to watch and evntually concluded that every single WB disk was bad, even some that weren't even opened. It was unique to WB, other companies disks continued to mostly work.

Some people online at the time mentioned WB replaced a few of their disks with bluray's but I never managed to get WB to respond to my inquiries.

I ended up flying the jolly roger, I mean I own a legal copy, so its just format shifting...