Submit operation failed - NotFound from RIA Services with Silverlight 4 on SubmitChanges()

I'm using SL4 and RIA Services to build a new solution based on the Silverlight Business Application template. Since I'm still developing, I'm just using localhost.

I'm trying to test the SubmitChanges functionality by making a single change in an associated (composition) entity and calling SubmitChanges. I have a breakpoint in my DomainService at the entry point in the Update method. The breakpoint is hit and everything looks okay. At this point, I don't actually have the Update method do anything - it simply returns. In the client-side callback, I check the SubmitOperation object for errors. It reports:

Submit operation failed.  The remote server returned an error: NotFound.

So far I haven't found what wasn't found.

I tried using Fiddler (along with the WCF Binary plugin) and as far as I can tell, the request looks good, but according to Fiddler:

ReadResponse() failed: The server did not return a response for this request. 

Hmm... Well that can't be right because my callback breakpoint was hit. (That's how I got the NotFound error message.)

I also tried editing my web.config file with the following:

<system.serviceModel>
  <serviceHostingEnvironment aspNetCompatibilityEnabled="true" multipleSiteBindingsEnabled="tru开发者_JAVA百科e" />
  <behaviors>
    <serviceBehaviors>
      <behavior name="RIAServiceBehavior">
        <serviceMetadata httpGetEnabled="true" />
        <serviceDebug includeExceptionDetailInFaults="True" />
      </behavior>
    </serviceBehaviors>
  </behaviors>
</system.serviceModel>

That didn't provide any new information. I'm starting to run out of ideas on how to track down the "real" problem. Any ideas??

Saurabh and Dan both have good posts on debugging 'Not Found' exceptions.

http://blogs.msdn.com/b/saurabh/archive/2010/03/16/ria-services-application-deployment.aspx

http://blogs.objectsharp.com/post/2010/04/13/WCF-RIA-Services-%E2%80%9CNot-Found%E2%80%9D-Error-Message.aspx

Kyle