Stadsing A/S - Shop

An error occured while attaching module (Dynamicweb.Frontend.Content)

System.NullReferenceException: Object reference not set to an instance of an object.
   at Dynamicweb.eCommerce.Products.Group.get_AllGroupsByLanguageID(String languageID)
   at Dynamicweb.eCommerce.Products.Group.get_GroupByID(String groupID, String languageId, String defaultLanguageId)
   at Dynamicweb.eCommerce.Products.Group.GetGroupsByIDs(IEnumerable`1 groupIDs, Boolean applyFiltering, String languageId, String defaultLanguageId)
   at Dynamicweb.eCommerce.Products.ProductGroupRelationCollection.get_GroupCollection()
   at Dynamicweb.eCommerce.Frontend.Renderer.IsProductInRightShopContext(Product product)
   at Dynamicweb.eCommerce.Frontend.Frontend.EcomRender()
   at Dynamicweb.eCommerce.Frontend.Frontend.GetContent()
   at Dynamicweb.Frontend.Content.GetModule(DataRow& ParagraphRow)