WCF Cast error "Unable to cast object of type 'X' to type 'X'

I develop WCF Publisher/Subscriber model, Publisher to develop in WCF service library and to host in windows service, its running fine. After to create a Pro开发者_JAVA技巧xy for that endpoints using 'SvcUtil'. and to merge to subscriber to develop in windows application. when i connect to publisher,

I get error "WCF Cast error "Unable to cast object of type 'X' to type 'X'"

i debug the code this line to rise the error IEvent Subscriber = OperationContext.Current.GetCallbackChannel();

Perhaps you should take a look at:

• http://social.msdn.microsoft.com/Forums/en-US/wcf/thread/f31155d4-b50d-4b8e-988f-a91a55d399fa/
• http://social.msdn.microsoft.com/Forums/en-US/wpf/thread/bff60bca-fe62-42ff-b04f-a3265aeca719/
• http://blogs.microsoft.co.il/blogs/kolbis/archive/2008/06/29/unable-to-cast-object-from-type-x-to-type-x.aspx