I'm no expert, rely on the statement of my Apple dealer (Fa Wehmeyer.): On my burner (new with all updates), with whom I next DVD, CD also can burn BluRay, he throws me every Verbatim blank with error message out! I second the burning drive, with which I can only DVD and CD burning, he assumes the blanks and burn without any problems. What immediately caught my eye: the blanks have a razor-sharp edge protruding downwards. My Apple dealer thinks now that these sharp edge may be the reason why BluRay burner do not like these blanks, since the larger BluRay burners lens may be damaged by this sharp protruding edge and the burner the Verbatim blanks quickly spits. If I had not the good fortune to have two burning drives, I could throw away the 100 blanks!