While researching this issue, I found a number of other example pages where the narrative text generation fails and the page is left with a "Error processing narrative" message. I have tracked this down to a couple of issues with the build process - specifically in the Publisher and NarrativeGenerator classes. I also found that the tools java projects do not have the latest JsonParser, XMLParser and model classes as the AuditEvent class is missing and the SecurityEvent class is still there.