getting crossdomain error in silverlight and clientaccesspolicy 304 error

Question

I need to write some data to the DB from a Silverlight 4 application.

I'm using a Silverlight Enabled WCF Web Service. I've published it to IIS7 and added a ClientAccessPolicy.xml file to the inetpub/wwwroot (among other places) so I can access localhost/ClientAccessPolicy.xml just fine. I also added crossdomain.xml just in case.

I also have a Silverlight4 client app which accesses this service and runs through VS2010 on development server.

When trying to invoke a method in the WebService I'm getting a crossdomain error although I have a crossdomain policy in place and the web service is working fine.

When using Fidler I see I'm getting a 304 error when the client app is trying to access the clientaccesspolicy.xml

If I also publish the client app to IIS7 (both under port 80), I can run it using a browser on the same machine with no problem. But when I try to access it on a different machine, I again get a crossdaomain error.

I tried everything but I can't find an answer for this problem anywhere! Please help!!

This is what my ClientAccessPolicy.xml looks like:

<?xml version="1.0" encoding="utf-8"?>
<access-policy>
    <cross-domain-access>
        <policy>
            <allow-from http-request-headers="SOAPAction">
                <domain uri="http://*"/> 
            </allow-from>
            <grant-to> 
                <resource path="/" include-subpaths="true"/> 
            </grant-to>
        </policy>
    </cross-domain-access>
 </access-policy>

Answer 1

I have struggled with this misleading error "crossdomain error" before and after reading your situation I can tell for sure that ClientAccessPolicy.xml configuration is not the issue here you should look elsewhere.

few things i would do

1. Check my client config & web service configs(double check endpoints, behaviours and finally binding protocols) on the silverlight app.
2. Enable error logging for your wcf service.
3. Make sure you are passing the right authentication token to your web service (enable anonymous authentication for the web application hosting WCF service)).