Controller.Execute rendering as text file with no content type

When a 404 or 500 happens the page shows as a text file. The content type is empty in the response. How can I fix this so the content renders as a "text/html" page. ``` protected void Application_Error() { var context = new HttpContextWrapper(Context); if (!context.Request.IsAjaxRequest()) { var unhandledException = Server.GetLastError(); var httpException = unhandledException as HttpException; if (httpException == null) { var innerException = unhandledException.InnerException; httpException = innerException as HttpException; } var routeData = new RouteData(); routeData.Values.Add("controller", MVC.Errors.Name); if (httpException != null) { var httpCode = httpException.GetHttpCode(); switch (httpCode) { case (int)HttpStatusCode.NotFound: routeData.Values.Add("action", "PageNotFound"); Server.ClearError(); IController pageNotFoundController = new ErrorsController(); pageNotFoundController.Execute(new RequestContext(new HttpContextWrapper(Context), routeData)); break; } } else { routeData.Values.Add("action", "Error"); Server.ClearError(); IController errorController = new ErrorsController(); errorController.Execute(new RequestContext(new HttpContextWrapper(Context), routeData)); } } } ```