Error when deploying PersistenceUnit: IllegalArgumentException expecting collection type [boolean]

[antlia]

Since a week I'm getting this error when deploying my ear to JBoss EAP 6.2.0 19:48:56,355 ERROR [org.jboss.msc.service.fail] (ServerService Thread Pool -- 79) MSC000001: Failed to start service jboss.persistenceunit."Weare-0.1-dev.ear/WeAreEjb.jar#weareUnit": org.jboss.msc.service.StartException in service jboss.persistenceunit."Weare-0.1-dev.ear/WeAreEjb.jar#weareUnit": java.lang.IllegalArgumentException: Expecting collection type [boolean] at org.jboss.as.jpa.service.PersistenceUnitServiceImpl$1.run(PersistenceUnitServiceImpl.java:103) [jboss-as-jpa-7.3.0.Final-redhat-14.jar:7.3.0.Final-redhat-14] at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) [rt.jar:1.7.0_45] at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) [rt.jar:1.7.0_45] at java.lang.Thread.run(Thread.java:744) [rt.jar:1.7.0_45] at org.jboss.threads.JBossThread.run(JBossThread.java:122) [jboss-threads-2.1.1.Final-redhat-1.jar:2.1.1.Final-redhat-1] **Caused by: java.lang.IllegalArgumentException: Expecting collection type [boolean]** at org.hibernate.ejb.metamodel.AttributeFactory.determineCollectionType(AttributeFactory.java:902) at org.hibernate.ejb.metamodel.AttributeFactory$PluralAttributeMetadataImpl.<init>(AttributeFactory.java:756) at org.hibernate.ejb.metamodel.AttributeFactory$PluralAttributeMetadataImpl.<init>(AttributeFactory.java:737) at org.hibernate.ejb.metamodel.AttributeFactory.determineAttributeMetadata(AttributeFactory.java:520) at org.hibernate.ejb.metamodel.AttributeFactory.buildAttribute(AttributeFactory.java:100) at org.hibernate.ejb.metamodel.MetadataContext.wrapUp(MetadataContext.java:207) at org.hibernate.ejb.metamodel.MetamodelImpl.buildMetamodel(MetamodelImpl.java:83) at org.hibernate.ejb.EntityManagerFactoryImpl.<init>(EntityManagerFactoryImpl.java:106) at org.hibernate.ejb.Ejb3Configuration.buildEntityManagerFactory(Ejb3Configuration.java:914) at org.hibernate.ejb.Ejb3Configuration.buildEntityManagerFactory(Ejb3Configuration.java:899) at org.hibernate.ejb.HibernatePersistence.createContainerEntityManagerFactory(HibernatePersistence.java:76) at org.jboss.as.jpa.service.PersistenceUnitServiceImpl.createContainerEntityManagerFactory(PersistenceUnitServiceImpl.java:200) [jboss-as-jpa-7.3.0.Final-redhat-14.jar:7.3.0.Final-redhat-14] at org.jboss.as.jpa.service.PersistenceUnitServiceImpl.access$600(PersistenceUnitServiceImpl.java:57) [jboss-as-jpa-7.3.0.Final-redhat-14.jar:7.3.0.Final-redhat-14] at org.jboss.as.jpa.service.PersistenceUnitServiceImpl$1.run(PersistenceUnitServiceImpl.java:99) [jboss-as-jpa-7.3.0.Final-redhat-14.jar:7.3.0.Final-redhat-14] ... 4 more I've logged these classes: org.hibernate org.jboss.jpa org.jboss.service.msc Initially with log level ERROR, then TRACE, ending with ALL, but there is no trace of this error in log files...can anyone tell me which other classes are useful for logging this exception? I believed that org.hibernate was sufficient, because the exception is thrown by an hibernate class...