Ok, I suggest installing the latest oreo 8.1 firmware for your phone. Download the correct version for your phone, copy the firmware to SD card, do hard rest and after flash the firmware. Good luck
I had the same issue. But I installed Nova Launcher, set it as the default launcher and it didn't crash. But, a pretty big problem I have, now, is the horrid equalizer applied by default (seems to be something like Rock preset). Play Music doesn't have any useful options.
Quickstep Launcher doesn't work on my phone too, but downloading Nova Launcher solved the problem easily. Equalization problem is a little different.. and i don't think that a fix exists.