private void Application_Error(object sender, EventArgs e)
{
    var exception = Server.GetLastError();
#if !DEBUG
    exception.AddExceptionDataValue("User", User?.Identity?.Name);
    exception.HandleException();
#endif
    var httpException = exception as HttpException;
    if (httpException != null)
    {
        Response.StatusCode = httpException.GetHttpCode();
    }
    Server.ClearError();
    Response.TrySkipIisCustomErrors = true;
    IController controller = new ErrorController();
    var routeData = new RouteData();
    routeData.Values.Add("controller", "Error");
    routeData.Values.Add("action", "Index");
    routeData.Values.Add("message", exception == null ? "Details not available." : exception.Message);
    var rc = new RequestContext(new HttpContextWrapper(Context), routeData);
    controller.Execute(rc);
}