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

System.IndexOutOfRangeException: Index was outside the bounds of the array.
   at NCNL.Frederiksen.DW.Extenders.ProductExtender.ExtendTemplate(Template template)
   at Dynamicweb.Ecommerce.Frontend.Renderer.RenderProductTemplateExtenders(Product product, Template template, Boolean extendedProperties)
   at Dynamicweb.Ecommerce.Frontend.Renderer.RenderProduct(Product product, Boolean extendedProperties, Template template, Int32 loopCounter, Boolean renderRelated, String productUrl, Int32 quantity, Int32 wishListId, Boolean renderPublicList, Int32 orderLineOfProductCount)
   at Dynamicweb.Ecommerce.Frontend.Renderer.RenderProducts(ProductCollection products, Template parentTemplate, String loopName, Int32 loopCounter, Boolean renderRelatedProducts, Boolean renderRelatedLists)
   at Dynamicweb.Ecommerce.Frontend.Renderer.RenderProductRelatedGroups(Product product, Template parentTemplate, String loopName)
   at Dynamicweb.Ecommerce.Frontend.Renderer.RenderProduct(Product product, Boolean extendedProperties, Template template, Int32 loopCounter, Boolean renderRelated, String productUrl, Int32 quantity, Int32 wishListId, Boolean renderPublicList, 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)