If you don't see any Volusion products/orders downloading into Selro after one clicking the download button, please reset your Volusion API as per the steps below.
You can access the generic product export functions through the main Volusion API access page. In your Admin Area, go Inventory > Import/Export and click on the Volusion API tab.
Enabling generic exports is easy. Select Enable Public XML for Featured Products and Enable Public XML for All Products, then click Save next to each export option.