When you click on the first image in an ECommerce Gallery, you are asked "Are You Sure You Want to Empty the Cart?"
Typically this happens when you have your page containing the gallery set up with the incorrect template.
Head to Pages > All Pages > select the page with the ECommerce Gallery. On the page editing screen, look for Page Attributes > Template > choose either "default template", "page with sidebar", or "page without title". Update the page, and it should now be fully functional.