OK, so I turned logging up to DEBUG on all org.jboss so that I could get more information out of the server.log as I deploy. I removed all of the applications and deployed just this one to reproduce the error and ensure that I'm not looking at a different app. This is the bit of interest: 12:03:39,465 DEBUG [JBossXBDeployerHelper] Parsing file: ZipEntryHandler(a)10127346[path=webs/10.mpee.local.20080702.1257.ear/META-INF/persistence.xml context=file:/home/jim/messaging-platform/jboss-5.0.0.CR1/server/custom1/deploy/ real=vfszip:/home/jim/messaging-platform/jboss-5.0.0.CR1/server/custom1/deploy/webs/10.mpee.local.20080702.1257.ear/META-INF/persistence.xml] for type: class org.jboss.metadata.jpa.spec.PersistenceMetaData | 12:03:39,466 DEBUG [SaxJBossXBParser] Created parser: org.apache.xerces.jaxp.SAXParserImpl@153505d, isNamespaceAware: true, isValidating: true, isXIncludeAware: true | 12:03:39,467 DEBUG [SaxJBossXBParser] http://xml.org/sax/features/validation set to: true | 12:03:39,467 DEBUG [SaxJBossXBParser] http://xml.org/sax/features/namespaces set to: true | 12:03:39,467 DEBUG [SaxJBossXBParser] http://apache.org/xml/features/xinclude/fixup-language set to: false | 12:03:39,467 DEBUG [SaxJBossXBParser] http://apache.org/xml/features/xinclude/fixup-base-uris set to: false | 12:03:39,467 DEBUG [SaxJBossXBParser] http://apache.org/xml/features/validation/dynamic set to: true | 12:03:39,467 DEBUG [SaxJBossXBParser] http://apache.org/xml/features/validation/schema set to: true | 12:03:39,467 DEBUG [SaxJBossXBParser] http://xml.org/sax/features/validation set to: true | 12:03:39,467 DEBUG [SaxJBossXBParser] Created parser: org.apache.xerces.jaxp.SAXParserImpl@153505d, isNamespaceAware: true, isValidating: true, isXIncludeAware: true | 12:03:39,472 DEBUG [JBossEntityResolver] Cannot resolve [publicID=,systemID=persistence] | 12:03:39,472 DEBUG [JBossEntityResolver] Cannot resolve [publicID=null,systemID=] | 12:03:39,473 DEBUG [PersistenceUnitParsingDeployer] Error during deploy: vfszip:/home/jim/messaging-platform/jboss-5.0.0.CR1/server/custom1/deploy/webs/10.mpee.local.20080702.1257.ear | org.jboss.deployers.spi.DeploymentException: Error creating managed object for vfszip:/home/jim/messaging-platform/jboss-5.0.0.CR1/server/custom1/deploy/webs/10.mpee.local.20080702.1257.ear I've opened up the EAR and looked at the persistence.xml file and can see that the relevant code is in it. I'm wondering if this is down to the location of my persistence.xml file. I know that in JBoss4 there were problems when the persistence.xml was in the META-INF directory of the EAR instead of the META-INF directory in the jar that held the entities. I'll investigate this possibility as well. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4162029#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...