Have you tried removing you fingerprint, then going into Settings>Apps>Three Dots for More Option>Show System Apps>Biometrics>Force stop>Storage>Clear Data? Then try adding 2 fingerprints. Let me know if this helps.
Whenever I press the setting for fingerprint it gives me that error message. I will try to force stop biometrics but it does not let me view my fingerprints so I can't delete it
Having same issue. Biometric s won't let me add or delete fingerprint. I get the same error. Upsetting with a 2 month old phone. In frustration I've even done factory wipe and still a problem. Safe mode worked the first time but I dumped some apps and cleared cache, tried safe mode again and it no longer worked in safe mode. Phone heading out for service. I should have just stuck to my battery sucking iPhone.