I followed the workbook(Kyle Brown) to deploy the chapter 12 (First exercise) and got Cast exception when I launch the client and can not fix it. Here is the output of the screen WSCL0012I: Processing command line arguments. WSCL0013I: Initializing the J2EE Application Client Environment. WSCL0035I: Initialization of the J2EE Application Client Environment has completed. WSCL0014I: Invoking the Application Client class com.titan.paymentclient.TestPaymentClient WSCL0100E: Exception received: java.lang.reflect.InvocationTargetException: java.lang.ClassCastExcep tion ... I checked the jndi tree, the six entries works fine, and check the admin console, the processpayment is running and has nothing wrong. The client code I do believe is correct. So what could be the error source.