WAS8.5 deployed application error, want to know the cause of this error

Com. IBM. Websphere. Management. The application. Client. AppDeploymentException: ADMA0093E: An unexpected exception occurred while completing the task MapEJBRefToEJB. Exception: com. IBM. Websphere. Management application. Client. AppDeploymentException: Java. Lang. NullPointerException [Root exception is Java. Lang. NullPointerException] [Root exception is com. IBM. Websphere. Management application. The client. The AppDeploymentException: Java lang. NullPointerException [Root exception is Java. Lang. NullPointerException]]