Fingerprint fails after update: Often there are 2 issues,..
First check your Sensors in CIT menu <= dial this : * # * # 6 4 8 4 # * # *( or go settings/myphone/special Information click several times on kernel-version)
Now CIT-Menu opens, check gyro, FOD,...
If these are showing values they should work and you can go Calibrate FOD:
1) Please go in the CIT menu
2) Go in "3-dots" menu > Additional tools"
3) Find "fod fingerprint calibration"
screen scroll down calibrate the FOD
-> place a white thing (Paper, mirror) on FOD click start
before next step put somthing black on FOD and press next...
wait until finish close restart and add your fingerprint
If sensors are not working your persist partition seems to be corrupted!
In this case do following steps:
1.Download the latest Fastboot rom of our device from here (
https://c.mi.com/in/miuidownload/detail?guide=2).
2.Extract the downloaded package and navigate to images folder.
3.There you can find the persist.img file of your device.
4.Copy the file to your internal storage.
5.Reboot your device to TWRP and goto advanced/terminal
6.On the interface, type the following command.
Code:
simg2img /sdcard/persist.img /sdcard/persist_EXT4.img
7.If your code returns error like "Invalid sparse file format at header magic" as in my case then continue with the second line of code
Code:
dd if=/sdcard/persist.img of=/dev/block/bootdevice/by-name/persist
8.Else continue with this code
Code:
dd if=/sdcard/persist_EXT4.img of=/dev/block/bootdevice/by-name/persist
9.Simply reboot to system
Thx and have a nice day Chris