Silverlight SecurityException

I'm POSTing data to a server and successfully execute BeginGetRequestStream, then EndGetRequestStream, write my POST data to the fill the RequestStream, and call BeginGetResponse.

BeginGetResponse successfully returns and I then call:

Dim response As HttpWebResponse = CType(MyHttpRequest.EndGetResponse(asynchronousResult), Ht开发者_运维技巧tpWebResponse)

This line throws the folloing SecurityException Error:

{System.Security.SecurityException ---> System.Security.SecurityException: Security error.

at System.Net.Browser.BrowserHttpWebRequest.InternalEndGetResponse(IAsyncResult asyncResult)

at System.Net.Browser.BrowserHttpWebRequest.<>c__DisplayClass5.b__4(Object sendState)

at System.Net.Browser.AsyncHelper.<>c__DisplayClass2.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 EtsyV2NetSL.WebQuery.POST_ResponseCallback(IAsyncResult asynchronousResult)}

So my first thought was that I was being blocked by the server with their clientaccesspolicy.xml or crossdomain.xml. I've fired up Fiddler and saw the following:

GET http://openapi.etsy.com/clientaccesspolicy.xml > 596 (text/xml)
GET http://openapi.etsy.com/crossdomain.xml > 200 OK (application/xml)

So I checked their crossdomain.xml and the settings appear ok:

<!DOCTYPE cross-domain-policy SYSTEM "http://www.macromedia.com/xml/dtds/cross-domain-policy.dtd">
<cross-domain-policy>
   <allow-access-from domain="*"/>
</cross-domain-policy>

I've hit a dead end in trying to solve this problem. I'm running the test app on my dev machine from VS.

Does anyone have any ideas as to why Silverlight would be throwing this error?

Thanks

It seems like it's a client access policy issue, check this:

http://forums.silverlight.net/forums/p/26566/90867.aspx

It worked for me.

I dealt with a very similar problem today - however instead of an HTTP POST, I was attempting to do a WCF service call.

Here is the comment I placed in my code - please let me know if its not clear enough to be helpful.

// NB: Cross-domain bug
// If you end up here with a System.Security.SecurityException "Security error."
// Check that you're not trying to cross zones when making a service call
// (eg: Accessing Trigger Driver TimeSource service on http://IASWEB01/ when accessing the site via usertest.local
//  or any other URI with dots in it - yes it seems crazy)

This seems to be some security 'feature'. With the WCF call I got this exception even before the Silverlight client attempted to fetch the clientaccesspolicy.xml from the target host. Very annoying issue without a real solution in sight!