Why did my thumb scanner stop working

[AC Question]

I think my phone has reset itself. I normally use the thumb scanner to unlock my phone . Yesterday the thumb scanner option did not appear inst ad it keeps asking for a password and even my lock screen wallpaper is different now then before with the thumb scanner option. I have tried the Android Device Manager it will call the phone, locate the phone, but it will not unlock the screen when I change the password....What should I do

 

[the tall guy]

Hi, are you able to get into the phone using the password?