Active Directory might seem simple but it’s a very complex and delicate system. Active Directory is the holder of all your policies, users, and schemas. Also, several applications depend on the system. To your dismay, on a fine day, you encounter the below issue while changing something in user details or a simple reset of password.
In such a case, the first thing to do is not to panic. Otherwise, you may end up changing stuff and applying fixes without carefully evaluating the situation and possibly making it worst.