NOTE: During the production process there is a residue on the disc surface which doesn't always get removed although it should. If a Blu-ray disc is having issues being read then try carefully cleaning it. While Blu-ray discs are more scratch resistant one should always be careful. I normally use a damp microfiber cloth. If things are really bad (ie rental discs) I use either soapy water and then clean water so there's no soap left on the disc. Nonetheless, usually discs I am describing have trouble being seen by a Blu-ray drive to begin with. Once the film is cleaned off the disc then the issue vanishes. This has happened to me a number of times with import Blu-ray discs that I purchased online. Defective discs can be defective from the time of manufacturing, damaged in transport, or rentals being damaged, scratched, dirtied by moronic careless renters. Try cleaning the disc and if that fails then move on to exchanging for a replacement. In the end if cleaning a disc works it saves you a lot of extra work in having to get a replacement.
