Testing Flex Viewer 2.0 and getting the following error

[SallyGracia]

When I run & debug the Flex Viewer 2.0 in FLASH 4 I am getting the following error. I was using the previous version in Flex 3 and the maps were working fine.  All help is greatly appreciated!

SecurityError: Error #2048: Security sandbox violation: http://localhost/flexviewer/index.swf cannot load data from http://ont-charcsvr01/ArcGIS/rest/services/FouthOfJuly/MapServer?f=json.
at <anonymous>()
at mx.rpc::Responder/fault()
at mx.rpc::AsyncToken/http://www.adobe.com/2006/flex/mx/internal::applyFault()
at mx.rpc.events::FaultEvent/http://www.adobe.com/2006/flex/mx/internal::callTokenResponders()
at HTTPOperation/http://www.adobe.com/2006/flex/mx/internal::dispatchRpcEvent()
at mx.rpc::AbstractInvoker/http://www.adobe.com/2006/flex/mx/internal::faultHandler()
at mx.rpc::Responder/fault()
at mx.rpc::AsyncRequest/fault()
at DirectHTTPMessageResponder/securityErrorHandler()
at flash.events::EventDispatcher/dispatchEventFunction()

[DasaPaddock]

In the previous version you may have been running the app from the file system instead of http://localhost/. Try putting up a crossdomain.xml file at http://ont-charcsvr01/crossdomain.xml