Are you not able to login to your McAfee account? If your response is yes then this issue is something you have to fix immediately. As after logging to your account only you will have all the right to manage your McAfee products and subscription. The reason for you this issue can be incorrect username or password. So once the
reason is known you can fix the problem immediately but if you don't know the cause of the error then it is advisable to call McAfee Customer Care Number . This number stays put at all 24 hours to help the clients by eradicating their issue from the core.