IIS 404 Custom Error not working as expected

asp.netiisiis-6

I'm working on IIS6, ASP.NET, VS2008. The web site uses a custom error handler to catch 404 errors and serve an alternate page. When presented with an url of the form:

http://srv/crimson/articles/index

Everything works perfectly. But an url of the form:

http://srv/crimson/blog.aspx

Where blog.aspx does not exist, fails with the following message:

Server Error in '/Crimson' Application. Description: HTTP 404…

When I try and debug, none of the breakpoints in my 404 handler are hit. So it appears that something is catching the request earlier. Where? And how to I get it to pass the request on to my handler?

Edit
Thanks to those who answered, but none of those ideas worked. I've decided to attack the problem another way.

Best Answer

You might wanna try this:

In IIS6:

open "properties" for your website
go to "home directory" tab
click on "configuration"
look for the extension ".aspx"
click on "edit"
check the checkbox which says "verify that file exists"

edit

And what about this: http://msdn.microsoft.com/en-us/library/h0hfz6fc(VS.80).aspx

<customErrors defaultRedirect="sorry.htm" mode="On">  
     <error statusCode="404" redirect="NotFound.aspx"/>
</customErrors>

Since 'RemoteOnly' specifies that custom errors are shown only to the remote clients, and that ASP.NET errors are shown to the local host.

Related Solutions

Google 404 and .NET Custom Error Pages

There is a new redirect mode in ASP.NET 3.5 SP1 that you can now use so it doesn't redirect. It shows the error page, but keeps the URL the same:

"Also nice for URL redirects. If you set the redirectMode on in web.config to "responseRewrite" you can avoid a redirect to a custom error page and leave the URL in the browser untouched."

CustomErrorsSection.RedirectMode Property (MSDN)

Using Custom Domains With IIS Express

This is what worked for me (Updated for VS 2013, see revision history for 2010, for VS 2015 see this: https://stackoverflow.com/a/32744234/218971):

Right-click your Web Application Project ▶ Properties ▶ Web, then configure the Servers section as follows:
- Select IIS Express ▼ from the drop down
- Project Url: http://localhost
- Override application root URL: http://dev.example.com
- Click Create Virtual Directory (if you get an error here you may need to disable IIS 5/6/7/8, change IIS's Default Site to anything but port :80, make sure Skype isn't using port 80, etc.)
Optionally: Set the Start URL to http://dev.example.com

Open %USERPROFILE%\My Documents\IISExpress\config\applicationhost.config (Windows XP, Vista, and 7) and edit the site definition in the <sites> config block to be along the lines of the following:

<site name="DevExample" id="997005936">
    <application path="/" applicationPool="Clr2IntegratedAppPool">
        <virtualDirectory
            path="/"
            physicalPath="C:\path\to\application\root" />
    </application>
    <bindings>
        <binding
            protocol="http"
            bindingInformation=":80:dev.example.com" />
    </bindings>
    <applicationDefaults applicationPool="Clr2IntegratedAppPool" />
</site>

If running MVC: make sure the applicationPool is set to one of the "Integrated" options (like "Clr2IntegratedAppPool").
Open your hosts file and add the line 127.0.0.1 dev.example.com.
► Start your application!

Some great advice from the comments:

You may need to run Visual Studio as Administrator.

If you want to make other devs see your IIS run netsh http add urlacl url=http://dev.example.com:80/ user=everyone

If you want the site to resolve for all hosts set bindingInformation="*:80:". Use any port you want, 80 is just convenient. To resolve all hosts you'll need to run Visual Studio as an administrator

Best Answer

Related Solutions

Google 404 and .NET Custom Error Pages

Using Custom Domains With IIS Express

Related Topic