I'm trying to condense it into a smaller test case because of the large number of dependencies. The error kept popping up after a svn update because the delete of a HistoryProcessInstanceImpl was not cascaded to the set of historyActivityInstances. I changed the Hibernate configuration in jbpm.history.hbm.xml for that part to this: | <set name="historyActivityInstances" cascade="all" inverse="true"> | <key foreign-key="FK_HACTI_HPROCI" on-delete="cascade"> | <column name="HPROCI_" index="IDX_HACTI_HPROCI"/> | </key> | <one-to-many class="HistoryActivityInstanceImpl" /> | </set> | View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4242638#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...