I rooted my Mobile Device to test something in WhatsApp, tried bypass maximum members limit in a group, but the method didn’t work anymore.

But programs of my bank stopped working, they were disabled to work in rooted mobiles, I Unrooted Mobile but footprints of root were still existed and the bank program didn’t work.

I had to reinstall the entire Firmware, after hours of searching, I found how to do it, I’d like to share my experience to save time from anyone trying to do so.

This method essentially doesn’t require a rooted device and the Firmware only applicable to HUAWEI GR5 Firmware KII-L21

This will erase all data and apps and reset the phone’s software to the Firmware we use.

1. Download the official Firmware (1.5 GB) from this link https://1drv.ms/u/s!AjCoo32OvSxQlh7imzrmUmeLCjv3
2. Extract the file and put file UPDATE.APP in SD card in this path SD_CARD/dload/UPDATE.APP
3. Input this code in the phone’s dialer *#*#2846579#*#* and choose Software Upgrade
4. Phone restarts and install the new Firmware.

Congratulations, your phone is new.

After setting phone configuration, Update your phone
go to Settings -> Update, this will update Phone Firmware from KII-L21_C185B321CUSTC185D001 to KII-L21_C185B321CUSTC185D002