Archive for the ‘ASP.NET’ Tag

Alternate fix for IIS6 eurl.axd 404 error

With ASPNET 4.0 there is a breaking change when using IIS6 with a website that has “legacy” ASPNET 2.0 mixed with ASPNET 4.0 applications.

Extensionless URLs that used to be sent to your configured “default content page” such as “Default.aspx” will instead be sent to eurl.axd followed by a hash code. Unfortunately your ASPNET 2.0 application will not automatically handle that.

Microsoft provides 3 workarounds in its ASPNET V4 Breaking Changes document. Two of them are to not mix ASPNET 2.0 and 4.0 applications in the same web site. The third is to disable extensionless URLs altogether.

But what if you DO want to mix ASPNET 2.0 and 4.0 applications in the same website AND use extensionless URLs in your 4.0 application?

Why not just handle the eurl.axd path and redirect it to your default document? This worked for me:

1. Create a class library (i.e. eurlredirect.dll) with a single IHttpHandler class.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Web;

namespace eurlredirect
    public class RedirectHandler : IHttpHandler
        public bool IsReusable
            get { return true; }

        public void ProcessRequest(HttpContext context)

2. Add the class library to your ASPNET 2.0 bin directory.

3. Configure the handler in the ASPNET 2.0 application’s web.config file by adding the following entry to the <httpHandlers> section:

<add verb=”*” path=”eurl.axd” validate=”false” type=”eurlredirect.RedirectHandler, eurlredirect”/>