A NullPointerException was thrown when aborting a failed publication. This also happened when following the email notification sample with the former workflow version.

The fix is to make sure that org.jbpm.persistence.processinstance.JcrSignalManager.SignalAction and org.jbpm.persistence.processinstance.JcrSignalManager.SignalProcessInstanceAction don't just return null as they do in the jBPM implementation. Why this is needed, I don't know.. possibly just circumventing some weird bug in jBPM?