Hi, I am getting a ClassCastException (at runtime) while communicating between multiple ears. The deployment is carried out in weblogic 7 without any exceptions. Let me explain the complete deployment structure. I have 2 ears - 1. abc.ear - contains multiple jars a. helperClasses.jar - Containing simple classes and a utility Class which represent all the objects "utilClass.java". b. slb1.jar - remote stateless session bean used for testing. c. TestClient.jar - containing a test client. 2. xyz.ear - contains a. helperClasses.jar - same as 1a above b. slb2.jar - containing remote stateless session bean for procession the business logic. TestClient delegates the call to a method in slb1.jar which in turn delegates the call to a method in one of the helperClasses. The TestClient passes the object of the utilClass to the helperClasses. The method in the helperClass makes a remote call to one of the beans in slb2.jar which processes the business logic. The helperClass passes the object of the utilClass WRAPPED IN A LIST to slb2.jar. To process the logic slb2.jar extract the objects in the list and casts them back to utilClass. This is where I get a ClassCastException. However, if the above is done in 1 ear, everything works perfectly. Considering the manner in which the ClassLoader works, putting the helperClass in the CLASSPATH or Code Base can be an option but since I am looking at issues related to hot deployment, such option is not preferable. Any help in this regard will be greatly appreciated. Thanks in advance, Sachin.