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

System.NullReferenceException: Object reference not set to an instance of an object.
   at NoZebra.CustomWeb.CustomCode.ProductTemplateExtenderTecDocFilesAndImages.ExtendTemplate(Template template) in C:\Code\NAP\nap\NAP.Web\CustomCode\ProductTemplateExtenderTecDocFilesAndImages.cs:line 25
   at Dynamicweb.eCommerce.Frontend.Renderer.RenderProductTemplateExtenders(Product Product, Template Template)
   at Dynamicweb.eCommerce.Frontend.Renderer.RenderProduct(Product Product, Boolean ExtendedProperties, Template Template, Int32 loopCounter, Boolean renderRelated, String productURL)
   at Dynamicweb.eCommerce.Frontend.Renderer.RenderProduct(Product Product, Boolean ExtendedProperties)
   at Dynamicweb.eCommerce.Frontend.Frontend.EcomRender()
   at Dynamicweb.eCommerce.Frontend.Frontend.GetContent()
   at Dynamicweb.Frontend.Content.getModule(DataRow& ParagraphRow)