I had an ASP.NET 2.0 application, where I had used HttpHandler to write SEO friendly url. Now I had moved that app to ASP.NET 4.0 and was trying to use ASP.NET Routing. I tried simple way by creating route url in global.asax and then tried to access my routed url and I was getting following error.
ASP.NET 4.0 URL Routing HTTP Error 404.0 - Not Found The solution of this problem is to add below config into web.config under <system.webServer>
<add name="UrlRoutingModule" type="System.Web.Routing.UrlRoutingModule, System.Web, Version=184.108.40.206, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" />
Hope, this will help someone.