This is likely caused by the date set for "Stop accepting registrations after" and often occurs when the date is not updated after duplicating an event from a previous year.

To resolve:

  1. In Sphere, navigate to Communities>Special Events>Friends Asking Friends>Kintera Thon
  2. Hover over the event name and select Website Info
  3. Select Fee Structure
  4. Scroll to the Registration Types listed and click edit next to the registration type
  5. Next to Stop accepting registrations after, modify the date or unmark the box
  6. Repeat for any remaining registration types
  7. Click Save
  8. Navigate back to the Webinfo Checklist and click Publish This Event Now