Communication Exception with my WCF Service SL4 app

Question

Sorry if the Title is a little vague but the truth is I do not understand my problem, I have never come across this before and I havent done anything out of the Ordinary.

Right I have a basic Silverlight 4 Application using the Business Application Template. I have also created a WCF Service Application Project which is used to simply return an Observable collection for some entries in my Database,

I published this to my Local computer which I then referenced in my SL4 app and I get this exception

[System.ServiceModel.CommunicationException: The remote server returned an error:     NotFound. ---> System.Net.WebException: The remote server returned an error: NotFound. --->     System.Net.WebException: The remote server returned an error: NotFound.
at System.Net.Browser.BrowserHttpWebRequest.InternalEndGetResponse(IAsyncResult  asyncResult)
at System.Net.Browser.BrowserHttpWebRequest.<>c__DisplayClass5.  <EndGetResponse>b__4(Object sendState)
at System.Net.Browser.AsyncHelper.<>c__DisplayClass4.<BeginOnUI>b__0(Object sendState)
--- End of inner exception stack trace ---
at System.Net.Browser.AsyncHelper.BeginOnUI(SendOrPostCallback beginMethod, Object  state)
at System.Net.Browser.BrowserHttpWebRequest.EndGetResponse(IAsyncResult asyncResult)
at  System.ServiceModel.Channels.HttpChannelFactory.HttpRequestChannel.HttpChannelAsyncRequest.  CompleteGetResponse(IAsyncResult result)
--- End of inner exception stack trace ---
at System.ServiceModel.AsyncResult.End[TAsyncResult](IAsyncResult result)
at System.ServiceModel.Channels.ServiceChannel.EndCall(String action, Object[] outs,  IAsyncResult result)
at System.ServiceModel.ClientBase`1.ChannelBase`1.EndInvoke(String methodName, Object[]  args, IAsyncResult result)
at  RMServiceRIA.rService.Service1Client.Service1ClientChannel.EndgetBuildings(IAsyncResult  result)
at  RMServiceRIA.rService.Service1Client.RMServiceRIA.rService.IService1.EndgetBuildings(IAsync Result result)
at RMServiceRIA.rService.Service1Client.OnEndgetBuildings(IAsyncResult result)
at System.ServiceModel.ClientBase`1.OnAsyncCallCompleted(IAsyncResult result)}

I have got a clientaccess policy and crossdomain policy which for the purpose of testing is set to allow anything access,

Client Access Policy

Cross Domain

any ideas on how to fix this problem, I debugged my WCF Service and it receives the call, the method executed reaches its return statement, yet my SL4 never even receives the result, as soon as my WCF service has the result I get an exception thrown within my SL4 app, to me it just seems that the connection gets closed but I dont know and I have tried to research but where do you start with something you dont fully understand? I found many people with the same sort of error message but WCF is so damn cryptic... I did try and enable the debugging information inside of my webconfig. I have also tried to host the WCF service on my Web server but no luck, I have several WCF Services running on that with a similar set up so I am unsure why this isnt working

Web Config for WCF Service

client config

Thanks for having a look, and if you need any more info just ask I'll be happy to provide you with it,

Answer 1

Your best bet is to turn on WCF Tracing so you can see what is going on.

http://software.intel.com/en-us/blogs/2010/02/03/adventures-with-silverlight-and-wcf-the-remote-server-returned-an-error-notfound/

Most likely there is an issue with serializing something. Not found is just the Silverlight version of a 500 error.