Thanks Pete, I have now filled a JIRA relating to this issue. I've also done some further investigation and discovered that JBPM session is not null. The NPE is caused by a call to getTransactionManager().getTransaction() in Hibernates JTATransaction class that returns null. Its detailed in the jira issue: http://jira.jboss.org/jira/browse/JBSEAM-2575 I'll post in the jbpm forum shortly. BTW Please ignore the previous post about a possible related error "uninitialized proxy passed to save". I was accessing the jbpm context in a strange way. For some reason, I was calling: | JbpmContext jbpmContext = Jbpm.instance().getJbpmConfiguration().createJbpmContext() ; | instead of: | @In JbpmContext jbpmContext; | View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4126152#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...