Sorry guys, I put this option off and then back ON. Now it works. Strange behavior though.
I enabled the option "Encrypt device using Lock screen password"
When I restarted the phone, it asked for the password, but before I could enter it, it showed another screen that reads:
"
Thank you
Thank you for helping make MIUI better!
Username:
Password:
[Validate]
"
And I cannot proceed from there.
My device is a mi mix.
Any idea ?