Re: not yours
That's happened to me.
I've got a blu-ray box set of the original Planet of The Apes movies that became unviewable after I updated the firmware on my blu-ray player.
It was the only movie in my collection that was affected. I didn't update the firmware in our other blu-ray player and the movies are still viewable on that unit.
My Toshiba laptop that has an internal blu-ray won't play any blu-ray movies anymore either.
DRM is a disaster.