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

System.NullReferenceException: Object reference not set to an instance of an object.
   at DwCustomModules.CustomModules.ProductFilter.Frontend.GetTemplateTags(Group selectedGroup, ParagraphCollection pageParagraphCollection, Template template) in C:\Repositories\Medilink\Medilink Build\Application\CustomModules\ProductFilter\ProductFilter.cs:line 218
   at DwCustomModules.CustomModules.ProductFilter.Frontend.GetContent() in C:\Repositories\Medilink\Medilink Build\Application\CustomModules\ProductFilter\ProductFilter.cs:line 63
   at Dynamicweb.Frontend.Content.GetModule(DataRow& ParagraphRow)