You do not have a link list with a handle set to simple-stories-scrapbooking-ranges-papers, or you do and it's empty. Go ahead and create a link list called Simple Stories: Scrapbooking Ranges & Papers on your Navigation page and populate that link list with links that point to collections, to see collections listed here. Make sure the link list also has a handle set to simple-stories-scrapbooking-ranges-papers.