Usually I start by asking the owner if they stuff is backed up. If no, you hand the phone back and tell them to get it done. (It's costly to do it in the shop.) If yes you do a factory reset and start over. There are some other ideas about clearing cache but we don't have time to fool around in the shop setting. Too many jobs to get done.
My Verizon LG VS995 received the Oreo update on Monday. Bluetooth and Gallery apps are crashing so quickly that I can no longer use either of them. I restarted my phone to no avail. I looked at the possibility of uninstalling those (to re-install) but that is not an option since they came pre-installed on my phone. Any hints??