jbpm.default.cfg.xml is the culprit here. That is creating problem. And also, DB id generation is something which should not happen in the transaction context. Because after generating the id it will try to commit so that the same id is not taken by some other transaction. If it participate in the same transaction where the main flow is on then it will end up committing that. So you will get the exception you mentioned. This is an example jbpm.cfg.xml which seems to be working | <jbpm-configuration> | | <import resource="jbpm.businesscalendar.cfg.xml" /> | <import resource="jbpm.jpdl.cfg.xml" /> | | <process-engine-context> | <repository-service /> | <repository-cache /> | <execution-service /> | <history-service /> | <management-service /> | <task-service /> | <identity-service /> | <command-service name="txRequiredCommandService"> | <retry-interceptor /> | <environment-interceptor /> | <spring-transaction-interceptor/> | </command-service> | | <object class="org.jbpm.pvm.internal.id.DatabaseDbidGenerator"> | <field name="commandService"><ref object="txRequiredCommandService" /></field> | </object> | | <object class="org.jbpm.pvm.internal.id.DatabaseIdComposer" init="eager" /> | | <script-manager default-expression-language="juel" default-script-language="juel"> | <script-language name="juel" factory="org.jbpm.pvm.internal.script.JuelScriptEngineFactory" /> | </script-manager> | | <job-executor auto-start="false" /> | | <types resource="jbpm.variable.types.xml" /> | </process-engine-context> | | <transaction-context> | <repository-session/> | <db-session/> | | <message-session/> | <timer-session/> | <history-session/> | | <hibernate-session current="true"/> | </transaction-context> | | </jbpm-configuration> | View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4265270#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...