You do not have a link list with a handle set to air-filters-94-97-obs-7-3, or you do and it's empty. Go ahead and create a link list called Air Filters 94-97 'OBS' 7.3 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 air-filters-94-97-obs-7-3.