An exception of type 'System.ServiceModel.CommunicationException' occurred in System.ServiceModel.ni.dll but was not handled in user code

I am using visual studio 2012 for windows phone. But not able to access my WCFService which is running local box. But i am able to access live service.
The below exception i am getting each time.
What might be the reason? Can anybody help me and save my head?
 

 
An exception of type 'System.ServiceModel.CommunicationException' occurred in System.ServiceModel.ni.dll but was not handled in user code
If there is a handler for this exception, the program may be safely continued.