Export of studies available only on nearline storage throws NullPointerException

[vrindanayak]

2021-04-15 16:49:37,338 ERROR [org.jboss.as.ejb3.invocation] (Thread-23 (ActiveMQ-client-global-threads)) WFLYEJB0034: EJB Invocation failed on component RetrieveServiceEJB for method public void org.dcm4chee.arc.retrieve.impl.RetrieveServiceEJB.updateInstanceAvailability(org.dcm4chee.arc.retrieve.RetrieveContext): javax.ejb.EJBException: java.lang.NullPointerException
	at org.jboss.as.ejb3@19.0.0.Final//org.jboss.as.ejb3.tx.CMTTxInterceptor.invokeInOurTx(CMTTxInterceptor.java:258)
	..........
	at deployment.dcm4chee-arc-ear-5.23.3-psql.ear.dcm4chee-arc-retrieve-5.23.3.jar//org.dcm4chee.arc.retrieve.impl.RetrieveServiceImpl.updateInstanceAvailability(RetrieveServiceImpl.java:954)
	at deployment.dcm4chee-arc-ear-5.23.3-psql.ear//org.dcm4chee.arc.store.scu.impl.RetrieveTaskImpl.run(RetrieveTaskImpl.java:149)
	at deployment.dcm4chee-arc-ear-5.23.3-psql.ear//org.dcm4chee.arc.export.dicom.DicomExporter.export(DicomExporter.java:105)
	at deployment.dcm4chee-arc-ear-5.23.3-psql.ear.dcm4chee-arc-export-mgt-5.23.3.jar//org.dcm4chee.arc.export.mgt.impl.ExportManagerMDB.onMessage(ExportManagerMDB.java:114)
	..........
	Caused by: java.lang.NullPointerException
	at deployment.dcm4chee-arc-ear-5.23.3-psql.ear.dcm4chee-arc-retrieve-5.23.3.jar//org.dcm4chee.arc.retrieve.impl.RetrieveServiceEJB.updateInstanceAvailability(RetrieveServiceEJB.java:118)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

Caused by Issue#3026 - Update instance availability for instances on retrieve of studies from nearline storage to online/cache storage commit

Test Scenario : Retrieve Cache for Nearline Storage and then invoke DICOM Export