A large number of failed validations occurred. A validation of Pin failed for user %1. Cause: This could happen because of ...

A large number of failed validations occurred.

A validation of Pin failed for user %1.
Cause: This could happen because of an attacker is trying to lockout an user.
Resolution:
 Please refer to the logs to see if the validation is failing for the same user. If it is consider disabling the user.