This occurs because the delivery method has been marked to be blocked beginning at a certain time before the scheduled program event.  The affected event falls within this time frame between the sale and the event time.  Use the steps below to correct this issue: 
  1. In Tickets>Delivery Methods, highlight the row for the selected method. 
  2. Click Edit. 
  3. Unmark the checkbox to Block this delivery type [time] before the event.  
    Reduce the time before the event, so that the Sale does not fall within that range.