Yesterday I tried to view "The Naked Gun: From the Files of Police Squad! 35th Anniversary Steelbook [4K UHD]" on my Magnetar 800 MKII. The player tried to play it, but then it gave me an "unknown disc" and refused to play it. I hit eject, tried once again and got the same error. I thought perhaps it was a bad disc. Upon wiping the disc clean and inspecting it, it looked perfectly fine and would not play. I put the disc in my Panasonic UB9000. The Panasonic did play the disc, but it kept rotating through a Blue screen with a bunch of different languagees. I didn't screengrab it, but I can if it helps. But what was in English said something about 4k Ultra HD and something something. It just kept cycling the blue screens/languages until I hit the top menu button. It then took me to the main menu where I could play the film. First time I even encountered something like this. I guess I'm fortunate to have a secondary player to view this disc, but is this a disc authoring issue? I'm wondering why the Magnetar won't let me get to the top menu to play the disc. Has anyone else seen or experienced this?