Please explain more fully about the "warranty exception" This "bug" sounds like it is totally of Apple's making. I have this problem also and was told by tech support I would need to send it to an Apple service center, (as I am too remote on the island of Molokai, Hawaii to take it too an Apple store), with $500(!!) up-front, none of which would probably get credited back to me. My MacBook Air isn't even 4 years old, and I very painfully paid a bundle for it. I had my previous Dell desktop for nearly 10(!!) years. It had its problems here and there, but especially by allowing me to extend my service contract 3 times over, I was able to keep it going for that long of a time. This is my first Apple product---and it could very well be my last☹️.