[ http://jira.jboss.com/jira/browse/EJBTHREE-572?page=comments#action_12398911 ] Alexander Tsirel commented on EJBTHREE-572: ------------------------------------------- Now PersistenceUnitInfo.getNewTempClassLoader(); returns not null ClassLoader, but during start of jboss with toplink when there is a lookup for oracle.toplink.essentials.platform.server.jboss.JBossPlatform class with this classloader NPE is thrown. I added some output to toplink - here is the output for this lookup. 17:05:01,446 INFO [STDOUT] Inside PrivilegedAccessHelper, looking for: oracle.toplink.essentials.platform.server.jboss.JBossPlatform with classLoader: org.jboss.mx.loading.UnifiedClassLoader3@ad962c{ url=file:/C:/jboss-4.2.1.GA/server/default/tmp/deploy/tmp42933javaEEApplication.ear ,addedOrder=0} After this lookup we have: 17:05:01,462 WARN [ServiceController] Problem starting service persistence.units:ear=javaEEApplication.ear,jar=EJB.jar,unitName=first javax.persistence.PersistenceException: Exception [TOPLINK-28018] (Oracle TopLink Essentials - 2.0.1 (Build SNAPSHOT (02/08/2008))): oracle.toplink.essentials.exceptions.EntityManagerSetupException Exception Description: predeploy for PersistenceUnit [first] failed. Internal Exception: java.lang.NullPointerException at oracle.toplink.essentials.internal.ejb.cmp3.EntityManagerSetupImpl.predeploy(EntityManagerSetupImpl.java:653) at oracle.toplink.essentials.ejb.cmp3.EntityManagerFactoryProvider.createContainerEntityManagerFactory(EntityManagerFactoryProvider.java:178) at org.jboss.ejb3.entity.PersistenceUnitDeployment.start(PersistenceUnitDeployment.java:247) -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: http://jira.jboss.com/jira/secure/Administrators.jspa - For more information on JIRA, see: http://www.atlassian.com/software/jira