How can I unlock my phone after it has requested an alternative password that I don't know?

[AC Question]

How can I unlock my phone after it has requested an alternative password that I don't know

Fingerprint scanner is not recognising my fingerprint anymore and it is asking for an alternative password that I don't remember
Please help

 

[B. Diddy]

Re: How can I unlock my phone after it has requested an alternative password that I don't know

Welcome to Android Central! Which phone? You really need to remember these passwords--you're asked to select one for just this reason. Try one of these methods: https://support.google.com/nexus/answer/3388218?hl=en