Here are a number of reasons why events or tickets are not visible in the ticket shop. In most cases, this is due to one of the settings below that are not set correctly:
Check whether the status of the event is Confirmed on the Main tab of the event. Tickets can not be sold for events whose status is Option, To Be Confirmed or Cancelled. Change the status to Events - Main.
Go to Events - Tickets and check if the Online checkbox is checked for the ticket you want to sell.
Verify that the sales period is set correctly. Click on Events - Tickets on 'View details' behind the Ticket type to go to the details window and check if the Sales start and Sales ends times are correct.