I'm hoping someone can help with this. I'm currently running X Note Build 15 on my Galaxy Note 3 SM-N9005, and it works very well. I saw yesterday that X Note Build 16 was available, so I installed it. Everything seemed to work fine, until I went into Settings and tried to change Lock Screen from Swipe to Password. After I'd entered the password for the second time, Settings just seemed to lock, and then I had a notification that the external SD Card was OK to remove - it had unmounted it! I tried again, and this time it seemed to work OK but Lock Screen still said Swipe - it had ignored the input.
I had a backup of Build 15 so I'm OK for the time being, but I'd very much like to know why this strange behaviour might be happening. Hope someone can shed some light.