Last week, I tried to play the BR disc of Kubo and the Two Strings and found out that my Sony BR player did not recognize the disc or the front counter would start at 0, count up to 8 and stop. I have played other BR discs in the Sony since then and they performed very well. Fortunately, there was a DVD of Kubo in the Case and it played well.

Has anyone else encountered non-working BR discs?

Not necessarily "non-working" but very recently I bought the Scandinavian edition of The Boy and the Beast. While the film plays it freezes whenever I try to pause it or skip to another chapter. Only solution by then is to disconnect the power chord. I've never had any such issues with my Blu-Ray player before (Pioneer BDP-450K).

I firmly believe all of them are equally evil.

I have never encountered bad Blu-ray discs. I take it you mean discs that have problems like disc rot, etc.?
Have you tried to update the current version of the player's firmware if there is one available?

I have never encountered a bad disc either.
Firmware can often be the issue if a disc does not play properly.

I'm fairly sure I've run into one bad BD long ago. One of the earlier discs. However, I've run into more bad DVDs than HD-DVD and BD.

I haven't encountered any Blu-ray playback issues so far, however I've been hesitant to start collecting those premium priced Steelbook editions having read about various rust problems starting to develop on the outer cases which are after all made from steel so are guaranteed to eventually rust. At the end of the day they are just like biscuit tin metal and I don't ever recall managing to preserve a biscuit tin for more than a few years without it getting rather sad looking.

I can fully understand how depressing it would be to see them start to develop rust spots within a few years as illustrated by someone else here:
https://www.youtube.com/watch?v=te8j1FrIJ5w

I'm guessing by the time they reach the age of most of my laserdiscs (30+) they will look terrible.

The Kubo BR disc is the first non-working BlueRay disc that I have encountered. I looked into updating the firmware and confusion runs rampant. There are 3 versions listed on Sony's website. Since I have not found out which firmware version is in the player, it is hard to select which Sony version to select. I have downloaded v11 as a start.

Of all the video formats I have (CED, HD-DVD, LD, DVD, BR), I would have to say that HD-DVD has given me the most troublesome discs. In order of problems, I would have to say the formats are (in worst to best): HD-DVD, CED, LD, DVD and BR. HD-DVD discs have problems such as being unrecognized by the player or freezing on playback. CED discs either are dirty causing excessive skipping or are just plain worn-out. The LD's I have (so far) show little laserrot. I do have some Sony LD's (Mind's Eye and Odyssey into the Mind's Eye) that exhibit colored sparklies when played. DVD and BR discs are about equal in good quality playback with almost zero problems. This is why I was surprised that the Kubo BR disc would not play even though it is a very recent movie.

I have never encountered a single bad Blu Ray disc in my entire life. I find factory pressed Blu Ray discs to be very reliable and very scratch resistant.
I have not encountered many LD rotters, either. I would say that 80-90% of my LD discs work fine. The rotters I have are mostly from PDO UK but I have the feeling that
not all discs rot to death. I have a very early PDO UK discs from 1983 that has some speckles but beside that it still plays great so it seems its decaying process stopped at some stage.
The HD DVD discs I got in Germany are still working except for the Warner discs that are mostly no longer working. The Universal discs are still OK. The Japanese HD DVD discs
I got in Osaka such as Twilight Samurai however are still working like a charm. They have a Japanese IFPI code on them.
I have never encountered a bad CD that stopped working. In all, I am very satisfied with the current condition of my collection.

My copy of Skyfall freezes up. It happened the 2nd time I played it on whatever player. I got a replacement that works just fine.
No trace of any scratches... It's a mystery

My whole Rambo trilogy box set by Lion's Gate.

I bought the European Studio Canal release to replace them - coincidentally, before I discovered the problem in the earlier box set - and since I was planning on selling the Lion's Gate box set, I decided to check out the trivia tracks exclusive to that release first. About halfway into the movie - as well as the second movie - playback got glitchy, freezing, mosaic, and eventually just stopped entirely. I can't even remember if I bothered with the third movie, but I inspected all three discs and they all had this bronze-coloured blotching on them, similar to the old CD bronzing but much darker.

I tried contacting LG about replacement discs but their website is useless for this sort of thing and I don't know what else to do with that box set besides throw it in the trash.

At least the Studio Canal set has much better transfers so it's not that big of a loss.

I have a very early Sony player that I’ve never updated and won’t play a few things. One of them is the Criterion Life Aquatic but I don’t remember the others. It’s a short list but then I’ve got a half dozen LD players have have viewed hundreds of Laserdiscs over decades and never have I had one that just won’t play so to me, personally, I consider BR to be a great but sometimes unreliable format. Sure, you can update to fix the problem but that IS a problem to me since shipping non-working stuff has become much more acceptable in the HD era. Also, nobody has issues simply making a BR disc that will play the part that causes the problem is going to be ads, copyright protection or the menus, all of which I have zero respect or need for so they are their own worst enemy in this area.

I have a PS3 that of course plays everything but it’s also spent so much time updating that Sony should send me a check for the power consumption. What I love is when the power dies mid-update (the odds are good at some point this will happen) and you get the message that rebuilding the drive may take up to nine hours. Hhmm...how many LDs can I watch and how many SNES games can I play in nine hours...

BR is the best format ever ONCE ITS PLAYING but waiting for stuff to load just so I can skip it as fast as it will let me, and wait for more stuff to load so I can skip that is a total BS PITA and I’m extremely resentful of it. They do all they can to drive you to piracy or streaming which are way more straightforward methods of watching something. The people who pay actual $$$ just get threatended with prison for stealing when they start the movie.

I’m rebuying all my Ghibli movies on DVD and BR from GKids because they don’t promote biscuits and SUVs in the inserts and the commentary disclaimers are at the END of the movie where they should be!

Nope not Blu-Ray, but I did encountered a bad HD-DVD.

Recently got a blu-ray where the overlay menu were permanently visible during the movie. Rather serious authoring flaw and a wonder how it slipped past quality control. I suppose it is more common with mastering/authoring flaws than actual dead discs. Arrow sent out replacement discs for the new Cat O' Nine Tails release recently due to some error as well.

Have a copy of Anchor Bay BD21464 Let Me In. Not a mark on the disc. Played to about the 40 or so minute mark and started stuttering in the playback then picture freezes. Tried different player and comes up completely unreadable/unrecognized on that one.

I recently had to throw away a copy of Dune. It was a Dutch steelbook release. I've had it for years, always worked like a charm. All of sudden it doesn't work anymore. With my Lg player in plays for about 20 seconds and shows all kinds of distortion before freezing up. My Sony player already freezes up at 3 seconds. The disc won't let me skip chapters so i can't even get to the disc menu. The disc is perfect, not a single scratch! Very weird....

Have to buy a new copy now!