Hello @GailD0 ,
Your landing page likely expired naturally. The expiration date for Shoppable Landing Pages is the date that the landing page will expire, allowing you to set how long you want the page/promotion to be available. By default, the expiration date is set 6 months out, but you can choose an earlier date. You won't be able to choose a date further out than 6 months. However, the landing page can be extended 6 months out at any time while it is Active. Once Done you will need to recreate / copy it, and cannot extend the expiration date to turn it back to active.