Silverlight securityexception

for cross-domain issues add these 2 files to the root of your website clientaccesspolicy.xml

<?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>

crossdomain.xml

<?xml version="1.0" ?>
<cross-domain-policy>
<allow-access-from domain="*" />
</cross-domain-policy>

of course ,based on security change the files above