You have been invited to join the Editorial Board of one of the Frontiers journals, but you cannot accept the invitation because:

1.  You are already registered in Frontiers or Loop, and the invitation was sent to a different email than the one you used for your account. 
   • Add the email that was used for the invitation to your profile and then, accept the invitation. You will then be able to handle manuscripts sent to either email.
     
     
     
2. You created a Loop account, while accepting the invitation, but it seems that the action hasn't registered.
   • After you have registered, you return to the invitation and click on the 'accept' link again.