Hi, and getting a org.hibernate.HibernateException: null index column for collection: org.jbpm.graph.exe.ProcessInstance.instances EXception in the moment I start a Taskinstance (TaskIntance.start() ). The task instance has already the actor set, and everything seems to be well, but, when I start it, it throws the exception. Any Idea, or clue? Thanks in advance Fernando The code: protected void executeFirsTask(){ | JbpmContext ctx = JbpmConfiguration.getInstance().createJbpmContext(); | try{ | List<TaskInstance> tasks = ctx.getTaskMgmtSession().findTaskInstances(getUsername()); | | if (tasks!=null && tasks.size() >0){ | TaskInstance ti =tasks.remove(0); | ti.start(); //HERE Throws the ExceptioN! | ti.end(); | ctx.save(ti); | } | }finally{ | ctx.close(); | } | } View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4200554#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...