java.lang.NullPointerException after extending AppraisalsVO class in Oracle EBS R12.1.1.1
                    
 Hi all
                
                I create new class XXAppraisalsVO which extend AppraisalsVO  and make substitution and upload class and substitution to test server.
Everything is done well.
When try to open appraisal page I get the below error
Error Page  
Exception Details.  
 oracle.apps.fnd.framework.OAException: java.lang.NullPointerException
	at oracle.apps.fnd.framework.OAException.wrapperException(OAException.java:896)
	at oracle.apps.fnd.framework.OAException.wrapperException(OAException.java:870)
	at oracle.apps.fnd.framework.OAException.wrapperInvocationTargetException(OAException.java:993)
	at oracle.apps.fnd.framework.server.OAUtility.invokeMethod(OAUtility.java:211)
	at oracle.apps.fnd.framework.server.OAUtility.invokeMethod(OAUtility.java:153)
	at oracle.apps.fnd.framework.server.OAApplicationModuleImpl.invokeMethod(OAApplicationModuleImpl.java:762)
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