I am getting the following message when I debuged the application, could you please post your suggestions on this :
I appreciate for taking your time and replying to the message : 
Microsoft JScript runtime error: Unhandled Error in Silverlight Application 
Code: 4004    
Category: ManagedRuntimeError       
Message: System.Reflection.TargetInvocationException: An exception occurred during the operation, making the result invalid.  Check InnerException for exception 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.Net.WebClient.GetWebResponse(WebRequest request, IAsyncResult result)
   at System.Net.WebClient.OpenReadAsyncCallback(IAsyncResult result)
   --- End of inner exception stack trace ---
   at System.ComponentModel.AsyncCompletedEventArgs.RaiseExceptionIfNecessary()
   at System.Net.OpenReadCompletedEventArgs.get_Result()
   at NYSBridge.Utility.ArcGISLyrAndTblInfo.WebClient_OpenReadCompleted(Object sender, OpenReadCompletedEventArgs e)
   at System.Net.WebClient.OnOpenReadCompleted(OpenReadCompletedEventArgs e)
   at System.Net.WebClient.OpenReadOperationCompleted(Object arg)