Custom Error Page does not show even though I set CustomError="On"

Question

I am using Visual Studio 2012 with the MVC 4 Framework and would like to see the friendly error page of the shared folder, if an exception is unhandled. (I know, as a develepor I need to see the error details but I just wanted to test this setting)
So far I know that adding the following code in the system.web section of web.config should do the trick

<customErrors mode="On" />

Unfortunately instead of my friendly error page I get this:

Server Error in '/' Application.

Runtime Error Description: An application error occurred on the server. The current custom error settings for this application prevent the details of the application error from being viewed.

Details: To enable the details of this specific error message to be viewable on the local server machine, please create a tag within a "web.config" configuration file located in the root directory of the current web application. This tag should then have its "mode" attribute set to "RemoteOnly". To enable the details to be viewable on remote machines, please set "mode" to "Off".

 <!-- Web.Config Configuration File -->

 <configuration>
     <system.web>
         <customErrors mode="RemoteOnly"/>
     </system.web> </configuration> 

Notes: The current error page you are seeing can be replaced by a custom error page by modifying the "defaultRedirect" attribute of the application's configuration tag to point to a custom error page URL.

 <!-- Web.Config Configuration File -->

 <configuration>
     <system.web>
         <customErrors mode="On" defaultRedirect="mycustompage.htm"/>
     </system.web> </configuration>

I would like to do it as described and not with a workaround like adding an action to HomeController, setting routes or something.
A reference that this should work is the following:
http://pluralsight.com/training/players/PSODPlayer?author=scott-allen&name=mvc3-building-controllers&mode=live&clip=0&course=aspdotnet-mvc3-intro
(On left select the chapter "Action Filters" and skip to minute 3:30)

UPDATE (link changed):
http://pluralsight.com/training/Player?author=scott-allen&name=mvc4-building-m2-controllers&mode=live&clip=0&course=mvc4-building
(On top click on the thin line that states "Controller in ASP.NET MVC 4", then click on "Action Filters" and skip to minute 5:00)

Does anybody have a clue why I cannot see the friendly error page with the setting mentioned above?
Thanks in advance!

Answer 1

Here is step by step guide to doing this,

To start with, first set the “customErrors’s” mode property to ‘on’. (This specifies that custom errors are enabled.)

1. Code from Web.config

<system.web>

    <customErrors mode="On"></customErrors>

</system.web>

Below is my controller code, I have specified the HandleError attribute on the controller class. Also to generate an error I am throwing an exception from the Index action.

2. Code from HomeController.cs

[HandleError]
public class HomeController : Controller
{
    public ActionResult Index()
    {
    throw new Exception("Error Occured !");
    ViewBag.Message = "Welcome to ASP.NET MVC!";

    return View();
    }

    public ActionResult About()
    {
    return View();
    }
}

As you can see in the screenshot below, I have a Error.cshtml view defined inside the Shared folder of the Views folder.

3. Solution Explorer

Note that the Error.cshtml view (shown below) uses a model of ‘System.Web.Mvc.HandleErrorInfo’

4. Code from Error.cshtml

@model System.Web.Mvc.HandleErrorInfo

@{
    ViewBag.Title = "Error";
}

<h2>
    Sorry, an error occurred while processing your request.
</h2>

On running the project, instead of getting the yellow death screen now I get the following output.

Taken from this article

Update :

Try this out by creating a new project, this should and does work. I suspect that your Error.cshtml file may not have model as @model System.Web.Mvc.HandleErrorInfo or you may be having multiple Error.cshtml pages in different view folders.