fingerprint doesn't work anymore I forgot backup password

Samsung’s fingerprint sensor does not work 100% all the time. Sometimes, even a tiny speck on the screen or on the finger can lead to misreading. After several attempts of unsuccessful logins, usually five, the device will then ask you to enter the backup password.

There are two things that you can try to regain access to your phone.

1) By forcing the phone to ask for the registered Google account. This can be done by entering the wrong password 20 times. Once the popup shows asking for the Google account, make sure that you enter the correct credentials. Keep in mind that a Google account does not have to be a Gmail account. It can be a third party email with a separate password. If you enter the correct credentials, the device will be unlocked and will ask you to enter another password.

2) If you are unlucky and also forget the Google account credentials, the only way out is by performing a factory reset. There’s no other way than this. As the name suggests, the device will be restored to its factory state, which means everything will be deleted from your device’s internal storage,

For reference, here are the steps how to do a factory reset:

• Turn off the device.
• Press and hold the following three buttons at the same time: Volume Up key, Home key, and Power key.
• When the phone vibrates, release the Power key but continue to press and hold the Volume Up key and the Home key.
• When the Android System Recovery screen appears, release the Volume Up and Home keys.
• Press the Volume down key several times key to highlight ‘wipe data / factory reset.’
• Press Power button to select.
• Press the Volume down key until ‘Yes — delete all user data’ is highlighted.
• Press Power button to select and start the master reset.
• When the master reset is complete, ‘Reboot system now’ is highlighted.
• Press the Power key to restart the device.

I forget my backup password