[ http://jira.jboss.com/jira/browse/EJBTHREE-572?page=comments#action_12399226 ] Alexander Tsirel commented on EJBTHREE-572: ------------------------------------------- I was using toplinks property (taken from forums): <property name="toplink.target-server" value="oracle.toplink.essentials.platform.server.jboss.JBossPlatform"/> Although there is no such class I get NPE instead of ClassNotFound: Caused by: java.lang.NullPointerException at org.jboss.mx.loading.RepositoryClassLoader.findClass(RepositoryClassLoader.java:623) at java.lang.ClassLoader.loadClass(ClassLoader.java:306) at org.jboss.mx.loading.RepositoryClassLoader.loadClassImpl(RepositoryClassLoader.java:467) at org.jboss.mx.loading.RepositoryClassLoader.loadClass(RepositoryClassLoader.java:408) at java.lang.ClassLoader.loadClass(ClassLoader.java:251) at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:319) at java.lang.Class.forName0(Native Method) at java.lang.Class.forName(Class.java:242) at oracle.toplink.essentials.internal.security.PrivilegedAccessHelper.getClassForName(PrivilegedAccessHelper.java:98) at oracle.toplink.essentials.internal.ejb.cmp3.EntityManagerSetupImpl.findClass(EntityManagerSetupImpl.java:410) at oracle.toplink.essentials.internal.ejb.cmp3.EntityManagerSetupImpl.findClassForProperty(EntityManagerSetupImpl.java:416) at oracle.toplink.essentials.internal.ejb.cmp3.EntityManagerSetupImpl.updateServerPlatform(EntityManagerSetupImpl.java:316) at oracle.toplink.essentials.internal.ejb.cmp3.EntityManagerSetupImpl.predeploy(EntityManagerSetupImpl.java:567) The lookup was done by such temp classloader acquired in predeploy method: 16:01:29,030 INFO [STDOUT] Inside PrivilegedAccessHelper, looking for: oracle.toplink.essentials.platform.server.jboss.JBossPlatform with classLoader: org.jboss.mx.loading.UnifiedClassLoader3@1813c12{ url=file:/C:/jboss-4.2.1.GA/server/default/tmp/deploy/tmp17799javaEEApplication.ear ,addedOrder=0} There are some notes in the internet about that, hope they'll help resolving issue: http://forums.oracle.com/forums/thread.jspa?messageID=2186220&#2186220 https://glassfish.dev.java.net/issues/show_bug.cgi?id=3721 -- 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