CiviCRM 4.6.3 and Drupal 7.38. I have gotten past credit card and CVV checks, verified info on Confirmation page, submitted the event registration, but browser comes back with "Page Not Found - The requested page '/civicrm/event/register' could not be found." When I check the CiviEvent Dashboard I see that the individual and any guest have been properly registered. CiviEvent is just not finding/displaying the Thank You page. That address seems strange. As a test I set up a CiviContribution page and ran through a contribution without a hitch. So I don't understand what is happening with CiviEvent. Ideas?