Our data is hosted on ArcGIS Server 10.0 Every request goes through a proxy server. So the clientaccesspolicy.xml is NOT allowing my silverlight to access the REST endpoint.
Code: 4004 Cannot access REST endpoint.
This only happens when using my local web dev sever in VS 2010. If the network admin opens up the proxy (*) - then anyone can access it (including my test server in Silverlight), but this is obviously a security issue.
Question: How do you alter the clientaccesspolicy.xml (or the proxy server) to allow a local VS web server (http://localhost:port/projectsitename...) to access the REST end point?