System.NullReferenceException: Object reference not set to an instance of an object.
   at ASP._Page_Views_MacroPartials_Speedware_Tree_CourseDetailItem_cshtml.Execute() in d:\web\localuser\favrskovmusiksk.dk\public_html\Views\MacroPartials\Speedware\Tree\CourseDetailItem.cshtml:line 9
   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.Web.Mvc.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_MacroPartials_Speedware_SPWI_Tree_cshtml.Execute() in d:\web\localuser\favrskovmusiksk.dk\public_html\Views\MacroPartials\Speedware\SPWI_Tree.cshtml:line 101
   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.Web.Mvc.ProfilingView.Render(ViewContext viewContext, TextWriter writer)
   at Umbraco.Web.Mvc.ControllerExtensions.RenderViewResultAsString(ControllerBase controller, ViewResultBase viewResult)
   at Umbraco.Web.Macros.PartialViewMacroEngine.Execute(MacroModel macro, IPublishedContent content)
   at Umbraco.Web.Macros.MacroRenderer.<>c__DisplayClass17_0.<ExecuteMacroOfType>b__0()
   at Umbraco.Web.Macros.MacroRenderer.ExecuteProfileMacroWithErrorWrapper(MacroModel macro, String msgIn, Func`1 getMacroContent, Func`1 msgErr)
   at Umbraco.Web.Macros.MacroRenderer.ExecuteMacroWithErrorWrapper(MacroModel macro, String msgIn, String msgOut, Func`1 getMacroContent, Func`1 msgErr)
   at Umbraco.Web.Macros.MacroRenderer.ExecuteMacroOfType(MacroModel model, IPublishedContent content)
   at Umbraco.Web.Macros.MacroRenderer.Render(MacroModel macro, IPublishedContent content, IDictionary pageElements)
   at Umbraco.Web.Macros.MacroRenderer.Render(String macroAlias, IPublishedContent content, IDictionary`2 macroParams)
   at Umbraco.Web.UmbracoComponentRenderer.RenderMacro(IPublishedContent content, String alias, IDictionary`2 parameters)
   at Umbraco.Web.UmbracoComponentRenderer.RenderMacro(Int32 contentId, String alias, IDictionary`2 parameters)
   at Umbraco.Web.UmbracoHelper.RenderMacro(String alias, IDictionary`2 parameters)
   at ASP._Page_Views_Partials_grid_editors_Macro_cshtml.Execute() in d:\web\localuser\favrskovmusiksk.dk\public_html\Views\Partials\grid\editors\Macro.cshtml:line 15
   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.Web.Mvc.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:\web\localuser\favrskovmusiksk.dk\public_html\Views\Partials\grid\editors\Base.cshtml:line 20