Large Ensembles

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

System.NullReferenceException: Object reference not set to an instance of an object.
   at Dynamicweb.Ecommerce.Products.Categories.Category.GetCategoryById(String categoryId, String languageId)
   at Dynamicweb.Ecommerce.Products.GroupRepository.ExtractGroup(IDataReader dataReader)
   at Dynamicweb.Ecommerce.Products.GroupRepository.GetGroups()
   at Dynamicweb.Ecommerce.Products.GroupService.GetCachedGroups()
   at Dynamicweb.Ecommerce.Products.GroupService.GetAllGroupsByLanguageId(String groupLanguageId)
   at Dynamicweb.Ecommerce.Products.GroupService.GetGroupById(String groupId, String languageId, String defaultLanguageId)
   at Dynamicweb.Ecommerce.Products.GroupService.GetGroup(String groupId, String languageId, String defaultLanguageId)
   at Dynamicweb.Ecommerce.Products.GroupService.GetGroups(IEnumerable`1 groupIds, Boolean applyFiltering)
   at Dynamicweb.Ecommerce.Products.ProductGroupRelationCollection.get_GroupCollection()
   at Dynamicweb.Ecommerce.Frontend.Renderer.RenderProduct(Product product, Boolean extendedProperties, Template template, Int32 loopCounter, Boolean renderRelated, String productUrl, Int32 quantity, Int32 wishListId, Boolean renderPublicList, Boolean isRecursiveCall, Lazy`1 categoryFieldSorting, Int32 orderLineOfProductCount)
   at Dynamicweb.Ecommerce.Frontend.Renderer.RenderProduct(Product product, Boolean extendedProperties)
   at Dynamicweb.Ecommerce.Frontend.Frontend.RenderProduct(Product product)
   at Dynamicweb.Ecommerce.Frontend.Frontend.EcomRender()
   at Dynamicweb.Ecommerce.Frontend.Frontend.GetContent()
   at Dynamicweb.Frontend.Content.GetModuleOutput(Paragraph paragraph, PageView pageview)
Demo