If you are trying to login to an iPhone app using your Fingerprint ID, you may receive a message that the app can no longer identify your fingerprint.
We are unable to verify your fingerprint. Please try again after you add your fingerprint in Settings.
If you recently deleted and re-added new fingerprints on your iPhone, all associated apps will need access to your new fingerprint in order for you to access them this way. This message will generally appear when you delete your old fingerprints on your iPhone and setup a new fingerprint.