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

System.NullReferenceException: Object reference not set to an instance of an object.
   at Co3.Abena.Website.Extender.ProductExtender.ExtendTemplate(Template template) in C:\Development\git\abena-solution\Co3.Abena.Website\Extender\ProductExtender.cs:line 28
   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.internalRenderProducts(ProductCollection products, Boolean isProductsFromIndex)
   at Dynamicweb.eCommerce.Frontend.Frontend.ListProducts(ProductCollection products, String groupsIdent, Boolean hasBeenSorted)
   at Dynamicweb.eCommerce.Frontend.Frontend.List(String groups)
   at Dynamicweb.eCommerce.Frontend.Frontend.EcomRender()
   at Dynamicweb.eCommerce.Frontend.Frontend.GetContent()
   at Dynamicweb.Frontend.Content.GetModule(DataRow& ParagraphRow)