Android stuck on "installing stsyem update" 8.1. It keeps rebooting and doesn't power off

[Android Central Question]

This morning I have downloaded the update for the system 8.1 and after the download was complete, I was asked to install the update. I did it, but the phone is now (after a few hours) still in this process, in a weird way.

It keeps rebooting and entering in the installation cycle, but the progress bar doesn't go further than about 25%. I cannot power the device off. Do you have any idea on how I can restore a previous version of the system or how can I move from this situation?

Thank you very much for your help,
Ugo

 

[B. Diddy]

Re: Android stuck on "installing stsyem update" 8.1. It keeps rebooting and doesn't power off

Welcome to Android Central! Which phone? Was this update pushed over-the-air, or did you download it from some website and try installing it manually?