Why does Response.StatusCode = (int)HttpStatusCode.NotFound give me the generic error handler?
<p>I catch and redirect 404 errors to an Error controller \ views with the following code. </p>

<pre><code>Response.Clear();
Server.ClearError();
var routeData = new RouteData();
routeData.Values["controller"] = "Error";
routeData.Values["action"] = "HttpError";
routeData.Values["exception"] = exception;          

Response.StatusCode = 500;
//if http 404 redirect to http404 action
if (httpException != null)
{
    Response.StatusCode = httpException.GetHttpCode();
    switch (Response.StatusCode)
    {
        case 404:
            routeData.Values["action"] = "Http404";
            break;
    }
}
</code></pre>

<p>In the error controller if I set Response.StatusCode = (int)HttpStatusCode.NotFound I get the generic error handler, not the view I returned.  This only seems to happen in production. Any ideas why?</p>

<pre><code>[AllowAnonymous]
public ActionResult Http404()
{
    //this line causes generic error handler
    Response.StatusCode = (int)HttpStatusCode.NotFound;

    var viewModel = new ErrorViewModel
    {
        Description = "Hmm, the page you're looking for can't be found"
    };

    return View("Error", viewModel);
}
</code></pre>