If there is a Friendly URL:
  1. Navigate to Communities > Special Events > Friends Asking Friends > Kintera Thon
  2. Hover over the event and click Website Info
  3. Next to the Friendly URL, click Edit 
    • Confirm the friendly URL excludes spaces - If there are spaces, remove them and click Submit. Then Navigate back to the Webinfo Checklist and click Publish This Event Now.

If that does not resolve the issue, Chat With Support and reference this article and please include the following information: 
  • Name of the event
  • URL of Event
  • The links that result in Page Not Found error