Why there is figerpy problem?

My phone's fingerprint is not working.. I can't run my all the apps secured by fingerprint lock..plsss help me.
It happened yesterday21-07-2018 when I opened my phone to run whatsup than I went for fingerprint I found no effect of my finger. Than it may be hanging so after sometime it will be ok.. but day and night have passed. Still it's not working. Plssss help me

Welcome to Android Central! Which phone? Are you able to unlock the phone using the fingerprint sensor? Does it work in Safe Mode?