graphic layer did not appears in map and caused error
i check both esri and my own services get the same error because graphic layer does not appear
in above sample i did not make any changes on esri sample even the esri services but still got the error
dont know why graphic layer did not add i check other sample also http://help.arcgis.com/en/webapi/silverlight/samples/start.htm#Find in that sample graphic layer does not appear also and graphic layer does not appear occurs only when query the data, record appear in the table or combo box while click on the selected record gives error because graphic layer does not add in the map