You do not have a link list with a handle set to connectors-20-super-duty-6-7, or you do and it's empty. Go ahead and create a link list called Connectors 20 Super Duty 6.7 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 connectors-20-super-duty-6-7.