Hi to understand a Catch Message Event, I downloaded a example in jBPM master and it works fine when i tested from JBDS - BPM editor platform. This test worked fine in eclipse based editor.
When I created a similar process in BPMs Console, I was not able to build & deploy as i was getting a problem. Highlighted the same in the screenshot
Test class
ksession.getWorkItemManager().registerWorkItemHandler("Human Task", new DoNothingWorkItemHandler());
ProcessInstance processInstance = ksession.startProcess("IntermediateCatchEvent");
assertTrue(processInstance.getState() == ProcessInstance.STATE_ACTIVE);
ksession = restoreSession(ksession, true);
// now signal process instance
ksession.signalEvent("MyMessage", "SomeValue", processInstance.getId());
assertProcessInstanceCompleted(processInstance.getId(), ksession);