Hello,
I updated from LOS 14.1 to LOS 15.1 yesterday.
I created a backup in TWRP (twrp-3.2.1-0-kipper-20180110).
After updating, the system was still running.
I didn't like LOS 15.1 because it looks so different, so I restored the backup in TWRP.
Since then, the device is in a bootloop, and I'm...