Reason for "Ticket not available" message on the checkout page

Question

There are various reasons why your tickets are not visible on the event checkout page. To know the issues, check for the following things:

1. Is the ticket/registration created for your event
2.  If the ticket is created, what are the start and end date and time for it?
3. Have you created a category but forgot to associate tickets with it.
4. Did you select a session but missed creating them