I see Pete has replied to a lot of posts so I hope I don't get missed this time. I really can't turn on <transaction:ejb-transaction/> in my application. It's always the same error. And it's difficult to debug since it's the AS that throws an error. I found two topics: http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4071599 http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4077142 That both end up with the same JIRA issue: http://jira.jboss.com/jira/browse/JBSEAM-1771 Unfortunately even after CR1 this doesn't work in my environment. opps, I saw Pete has replied (happy :) I use JBoss 4.2.1.GA, Seam 2.0.0.CR1. I access an Oracle 10g database. Here is my persistence.xml | <?xml version="1.0" encoding="UTF-8"?> | <persistence xmlns="http://java.sun.com/xml/ns/persistence" | xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" | xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd" | version="1.0"> | <persistence-unit name="examCenterDatabase" transaction-type="JTA"> | <provider>org.hibernate.ejb.HibernatePersistence</provider> | <jta-data-source>java:SeamDS</jta-data-source> | <properties> | <property name="hibernate.show_sql" value="true"/> | <property name="hibernate.max_fetch_depth" value="3"/> | <property name="hibernate.cache.provider_class" value="org.hibernate.cache.HashtableCacheProvider"/> | <!-- Oracle specific settings --> | <property name="hibernate.dialect" value="org.hibernate.dialect.Oracle10gDialect"/> | <property name="hibernate.connection.driver_class" value="oracle.jdbc.OracleDriver"/> | <!-- JBoss AS specific settings --> | <property name="hibernate.transaction.manager_lookup_class" | value="org.hibernate.transaction.JBossTransactionManagerLookup"/> | ... | </properties> | </persistence-unit> | </persistence> | and components.xml | <?xml version="1.0" encoding="UTF-8"?> | <components xmlns="http://jboss.com/products/seam/components" | xmlns:core="http://jboss.com/products/seam/core" | xmlns:security="http://jboss.com/products/seam/security" | xmlns:mail="http://jboss.com/products/seam/mail" | xmlns:persistence="http://jboss.com/products/seam/persistence" | xmlns:transaction="http://jboss.com/products/seam/transaction" | xmlns:theme="http://jboss.com/products/seam/theme" | xmlns:international="http://jboss.com/products/seam/international" | xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" | xsi:schemaLocation="http://jboss.com/products/seam/components http://jboss.com/products/seam/components-2.0.xsd | http://jboss.com/products/seam/core http://jboss.com/products/seam/core-2.0.xsd | http://jboss.com/products/seam/security http://jboss.com/products/seam/security-2.0.xsd | http://jboss.com/products/seam/mail http://jboss.com/products/seam/mail-2.0.xsd | http://jboss.com/products/seam/persistence http://jboss.com/products/seam/persistence-2.0.xsd | http://jboss.com/products/seam/transaction http://jboss.com/products/seam/transaction-2.0.xsd | http://jboss.com/products/seam/theme http://jboss.com/products/seam/theme-2.0.xsd"> | | <core:init jndi-pattern="java:comp/env/ExamCenter-EE/#{ejbName}/local" debug="true"/> | | <core:manager conversation-timeout="120000" | concurrent-request-timeout="500" | conversation-id-parameter="cid"/> | | <persistence:entity-manager-factory name="examCenterEntityManagerFactory" | persistence-unit-name="examCenterDatabase"/> | <persistence:managed-persistence-context name="entityManager" auto-create="true" | entity-manager-factory="#{examCenterEntityManagerFactory}"/> | <transaction:ejb-transaction/> | | ... | </components> | View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4086597#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...