ASP.NET MVC Custom Error page (StatusCode 404 throws a 500)

Question

I've got customErrors set in my web.config

<customErrors mode="On" defaultRedirect="/Error/GeneralError">
    <error statusCode="404" redirect="/Error/NotFound"/>
</customErrors>

This works fine locally. A 404 throws a 404. On the shared hosting it throws up the standard server 404 page unless I specifically set 404 to point to /Error/NotFound. That's fine. Now it will show the custom 404 page except the response status code is 200. So if I try to throw Response.StatusCode = 404; in my NotFound action in ErrorController like this:

public class ErrorController : Controller
{
    public ActionResult NotFound()
    {
        Response.StatusCode = 404;
        return View();
    }
}

the server throws a status code 500 Internal Server Error but my GeneralError page doesn't show, just a blank white page with no source.

I've tried many different combinations but I can't seem to find how to make it show my custom 404 page along with a 404 response.

Any ideas?

Is there any harm in allowing it to respond with 200 OK on a NotFound? Perhaps issues with web crawling or google webmaster tools. — mark123
Just a thought. Wouldn't it be better to use: defaultRedirect="~/Error/GeneralError" and redirect="~/Error/NotFound" with MVC applications. (Notice the ~ at the start of strings. This will map to the base of the application not the base of the domain... as you may know already.) — jwwishart

mark123 mark123 · Accepted Answer · 2010-03-04T04:21:28

I found out some interesting information here: http://blog.angrypets.com/2008/03/responsetryskip.html

Response.TrySkipIisCustomErrors = true;

Setting TrySkipIisCustomErrors to true after the Response.StatusCode = 404; takes care of the issue.

ASP.NET MVC Custom Error page (StatusCode 404 throws a 500)

2 Answers