I've had an issue with my Note 4 where the phone can suddenly freeze and lock up, it then switches itself off and reboots.
Has anyone else experienced something similar, if so did you find the root cause ?
My phone is a SIM free UK phone, i've recently cleared the cache from the boot menu and also a hard reset via the home button, power button and volume up button. The only app i have on at the moment is kaspersky Internet security 2016 and Aquamail, the phone is otherwise clear.
Mine started doing this a few weeks back. It would slow down to a crawl, freeze for a few seconds then restart. It got more and more frequent and eventually it started giving me an "mmc_read failed" error on bootup.
It's a common fault with Note 4s. I got mine repaired by Samsung ( new motherboard complete with a new metal frame. It was looking as good as new). I ended up recycling it and getting myself an s7 edge.



That stuff will be forwards compatible with whatever phone i buy next so why not