So the strangest thing happened to me over the last couple of days. Yesterday, I restarted my wife's iPhone 6S (iOS 8.4) and it would not accept the passcode. This is the same passcode we have been using for months, and it had not been changed. I tried it several times, and it just locked the phone. A hard restart did not help either. I eventually had to completely wipe the device and reinstall it, which really sucked because for some reason the phone was not backed up (iCloud full). So that was crazy enough because I could not find much on it at all. But then, this evening, she restarted her iPad, AND IT DID THE SAME THING!! The passcode was the same for both devices, and the iPad suddenly just started saying wrong passcode. I eventually had to do a full restore through iTunes. One work-around I found online was to hook it up to the computer and use iTunes to unlock it. That did not work for me because we did everything through the cloud so her devices have not been backed up to the computer. Trying to see if anyone has seen similar issues or knows what happened. If this happens again I don't want to have to reset the devices. (I've also made sure to have both computer and cloud backups of all devices. I will be reporting this to Apple. And no, neither of us changed the passcode and then forgot, nor were we entering the wrong passcode. This is the strangest and most random thing I have seen in 8 years of working on Apple devices.