You might have accidentally archived one of your programs. To open Archive,
Web:
1. Open your library (4 small squares in the top left corner)
2. Scroll down and click on 'Archive'
3. You can see your archived programs here.
4. To unarchive them, click on Unarchive.
App:
1. From the Home Screen, tap on the Side Bar icon (top left corner)
2. Tap on Archived Programs
3. To unarchive the program, tap on Unarchive button