System.NullReferenceException: Object reference not set to an instance of an object.
   at Umbraco.Web.PublishedContentExtensions.HasProperty(IPublishedContent content, String alias)
   at ASP._Page_Views_Partials_grid_editors_media_cshtml.Execute() in d:\Inetpub\VanMill\Views\Partials\Grid\Editors\Media.cshtml:line 13
   at System.Web.WebPages.WebPageBase.ExecutePageHierarchy()
   at System.Web.Mvc.WebViewPage.ExecutePageHierarchy()
   at System.Web.WebPages.WebPageBase.ExecutePageHierarchy(WebPageContext pageContext, TextWriter writer, WebPageRenderingBase startPage)
   at System.Web.Mvc.RazorView.RenderView(ViewContext viewContext, TextWriter writer, Object instance)
   at System.Web.Mvc.BuildManagerCompiledView.Render(ViewContext viewContext, TextWriter writer)
   at Umbraco.Core.Profiling.ProfilingView.Render(ViewContext viewContext, TextWriter writer)
   at System.Web.Mvc.HtmlHelper.RenderPartialInternal(String partialViewName, ViewDataDictionary viewData, Object model, TextWriter writer, ViewEngineCollection viewEngineCollection)
   at System.Web.Mvc.Html.PartialExtensions.Partial(HtmlHelper htmlHelper, String partialViewName, Object model, ViewDataDictionary viewData)
   at System.Web.Mvc.Html.PartialExtensions.Partial(HtmlHelper htmlHelper, String partialViewName, Object model)
   at ASP._Page_Views_Partials_grid_editors_base_cshtml.Execute() in d:\Inetpub\VanMill\Views\Partials\Grid\Editors\Base.cshtml:line 24