I get exactyl the same error.
13:56:12,531 SEVERE [org.jbpm.designer.web.profile.impl.JbpmProfileImpl] (http-localhost-127.0.0.1-8080-13) Could not find BPMNDI information: java.lang.IllegalArgumentException: Could not find BPMNDI information
at org.jbpm.designer.bpmn2.impl.Bpmn2JsonMarshaller.marshallProcess(Bpmn2JsonMarshaller.java:462)
...
Could anyone give a hint? Is this still a bug or a misunderstood modeling issue?
MyConfig: jBPM 5.4.0.final Windows 7 jBoss 7.0.2
Regards
Norman