System.NullReferenceException: Object reference not set to an instance of an object.
   at ASP._Page_Views_Helpers_Shareh5_cshtml.Execute() in e:\iis\sites\gpseducation.oecd.org\Views\Helpers\Shareh5.cshtml:line 36
   at System.Web.WebPages.WebPageBase.ExecutePageHierarchy()
   at System.Web.Mvc.WebViewPage.ExecutePageHierarchy()
   at System.Web.WebPages.StartPage.ExecutePageHierarchy()
   at System.Web.WebPages.StartPage.ExecutePageHierarchy()
   at System.Web.WebPages.WebPageBase.ExecutePageHierarchy(WebPageContext pageContext, TextWriter writer, WebPageRenderingBase startPage)
   at EaG.Controllers.HelpersController.RenderPartialViewToString(Controller controller, String viewName, Object model, String master)