Routing HTTP Error 404.0 0x80070002

The solution suggested

<system.webServer>
  <modules runAllManagedModulesForAllRequests="true" >
    <remove name="UrlRoutingModule"/>    
  </modules>
</system.webServer>

works, but can degrade performance and can even cause errors, because now all registered HTTP modules run on every request, not just managed requests (e.g. .aspx). This means modules will run on every .jpg .gif .css .html .pdf etc.

A more sensible solution is to include this in your web.config:

<system.webServer>
  <modules>
    <remove name="UrlRoutingModule-4.0" />
    <add name="UrlRoutingModule-4.0" type="System.Web.Routing.UrlRoutingModule" preCondition="" />
  </modules>
</system.webServer>

Credit for his goes to Colin Farr. Check-out his post about this topic at http://www.britishdeveloper.co.uk/2010/06/dont-use-modules-runallmanagedmodulesfo.html.

My solution, after trying EVERYTHING:

Bad deployment, an old PrecompiledApp.config was hanging around my deploy location, and making everything not work.

My final settings that worked:

• IIS 7.5, Win2k8r2 x64,
• Integrated mode application pool

• Nothing changes in the web.config - this means no special handlers for routing. Here's my snapshot of the sections a lot of other posts reference. I'm using FluorineFX, so I do have that handler added, but I did not need any others:

  <system.web>
    <compilation debug="true" targetFramework="4.0" />
    <authentication mode="None"/>
  
    <pages validateRequest="false" controlRenderingCompatibilityVersion="3.5" clientIDMode="AutoID"/>
    <httpRuntime requestPathInvalidCharacters=""/>
  
    <httpModules>
      <add name="FluorineGateway" type="FluorineFx.FluorineGateway, FluorineFx"/>
    </httpModules>
  </system.web>
    <system.webServer>
      <!-- Modules for IIS 7.0 Integrated mode -->
      <modules>
        <add name="FluorineGateway" type="FluorineFx.FluorineGateway, FluorineFx" />
      </modules>
  
      <!-- Disable detection of IIS 6.0 / Classic mode ASP.NET configuration -->
      <validation validateIntegratedModeConfiguration="false" />
    </system.webServer>
  

• Global.ashx: (only method of any note)

  void Application_Start(object sender, EventArgs e) {
      // Register routes...
      System.Web.Routing.Route echoRoute = new System.Web.Routing.Route(
            "{*message}",
          //the default value for the message
            new System.Web.Routing.RouteValueDictionary() { { "message", "" } },
          //any regular expression restrictions (i.e. @"[^\d].{4,}" means "does not start with number, at least 4 chars
            new System.Web.Routing.RouteValueDictionary() { { "message", @"[^\d].{4,}" } },
            new TestRoute.Handlers.PassthroughRouteHandler()
         );
  
      System.Web.Routing.RouteTable.Routes.Add(echoRoute);
  }
  

• PassthroughRouteHandler.cs - this achieved an automatic conversion from http://andrew.arace.info/stackoverflow to http://andrew.arace.info/#stackoverflow which would then be handled by the default.aspx:

  public class PassthroughRouteHandler : IRouteHandler {
  
      public IHttpHandler GetHttpHandler(RequestContext requestContext) {
          HttpContext.Current.Items["IncomingMessage"] = requestContext.RouteData.Values["message"];
          requestContext.HttpContext.Response.Redirect("#" + HttpContext.Current.Items["IncomingMessage"], true);
          return null;
      }
  }
  

The problem for me was a new server that System.Web.Routing was of version 3.5 while web.config requested version 4.0.0.0. The resolution was

%WINDIR%\Framework\v4.0.30319\aspnet_regiis -i

%WINDIR%\Framework64\v4.0.30319\aspnet_regiis -i

Uncheck this in Windows Explorer.

"Hide file type extensions for known types"

Having this in Global.asax.cs solved it for me.

protected void Application_Start()
{
    AreaRegistration.RegisterAllAreas();
    RouteConfig.RegisterRoutes(RouteTable.Routes);
}