Unable to Generate GSF ID SOLVED

I have a Z9X with the Google firmware installed. After a power failure I have the following error message :
"The device isn’t Play Protect certified" . I have followed the Zidoo guide to generate a GSF ID. Unfortunately no ID is generated. Any advice gratefully received. Thank you.

 

Maybe a factory reset?

Make sure you take a note of any settings and make a back up your HT library onto a USB stick or network location first!

 

Try to access into Google Play Store app and exit. Then check GSF ID in Settings.

 

Thanks - that was the solution in the end