1.  Confirm that the login name is entered exactly as it was created.  Login names can include capital letters and spaces.  

  • A participant's login name is in the confirmation email you received after registering.
  • A participant's login name can be located in Sphere. (How to locate a participant username)
2.  Confirm that they are accessing a site they have registered to.  Sphere logins are limited to the sites one is registered to.  If they have created more than one login name, make sure they are using the correct one. 
  • The confirmation email they have received after registering will have the login and event name.
3. If neither of the above addressed the issue, Chat with Support and reference this article.