Topic page is blank when I open it

If the app gets stuck whilst opening a topic page (only 'Learn Materials' heading is displayed) and you cannot click on the back button to return to the list of topics then you must try the following steps:

1. Close the app by pressing on the Home key
2. Reopen the app (the app will close again)
3. Reopen the app (you will return to the home screen)
4. Pull-refresh to re-sync the list of primers