CommunicationException was unhandled by user code - silverlight

Question

I created one solution and then added one project which contains all WCF services. Then i added it's reference to my Silverlight project in the same solution. Now when i try to debug i get one message box saying This Silverlight project you are about to debug is consuming web services. Calls to the web service will fail unless the project is executed in the context of the web which contains the web service. and still if i run it i get this error :-
An error occurred while trying to make a request to URI 'http://localhost:50318/CustomersService.svc'. This could be due to attempting to access a service in a cross-domain way without a proper cross-domain policy in place, or a policy that is unsuitable for SOAP services. You may need to contact the owner of the service to publish a cross-domain policy file and to ensure it allows SOAP-related HTTP headers to be sent. This error may also be caused by using internal types in the web service proxy without using the InternalsVisibleToAttribute attribute. Please see the inner exception for more details.
This is the detailed exception :-
{System.ServiceModel.CommunicationException: An error occurred while trying to make a request to URI 'http://localhost:50318/CustomersService.svc'. This could be due to attempting to access a service in a cross-domain way without a proper cross-domain policy in place, or a policy that is unsuitable for SOAP services. You may need to contact the owner of the service to publish a cross-domain policy file and to ensure it allows SOAP-related HTTP headers to be sent. This error may also be caused by using internal types in the web service proxy without using the InternalsVisibleToAttribute attribute. Please see the inner exception for more details. ---> System.Security.SecurityException ---> System.Security.SecurityException: Security error.
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__DisplayClass2.<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 MVVMDemo.CustomersServiceRef.CustomersServiceClient.CustomersServiceClientChannel.EndGetCustomers(IAsyncResult result)
at MVVMDemo.CustomersServiceRef.CustomersServiceClient.MVVMDemo.CustomersServiceRef.ICustomersService.EndGetCustomers(IAsyncResult result)
at MVVMDemo.CustomersServiceRef.CustomersServiceClient.OnEndGetCustomers(IAsyncResult result)
at System.ServiceModel.ClientBase`1.OnAsyncCallCompleted(IAsyncResult result)}
What should i do?
Thanks in advance:)

Answer 1

If your page hosting the silverlight control and the webservice you are trying to connect are in different domains(in ur case it looks like they are different projects) you will need to add the clientaccesspolicy.xml file to your website.
<?xml version="1.0" encoding="utf-8"?>
<access-policy>
<cross-domain-access>
<policy>
<allow-from http-request-headers="SOAPAction">
<domain uri="*"/>
</allow-from>
<grant-to>
<resource path="/" include-subpaths="true"/>
</grant-to>
</policy>
</cross-domain-access>
</access-policy>
Check out this link for more details