Gosh.. my phone's been running on Lollipop for ages, and I updated to different versions of marshmallow THRICE, and it gets stuck in a bootloop everytime. I tried wiping data, cache, factory reset, but nope. Whatever I do, as long as its on marshmallow, the phone goes into a bootloop, and the times when I manage to get into the main screen, it glitches and starts booting by itself. I flashed back to lollipop, and now I'm done. I even checked that the phone is compatible with marshmallow, but eh, still doesnt work. This is frustrating..