The process definition (attached) contains incorrect reference in attribute bpmnElement of bpmndi:BPMNPlane element. When I try to import this definition into Designer (after opening new BPMN2 process, using "Import from BPMN2") error message appears telling me "Failed to import BPMN2. Check server logs for more details."

There is no information about what is wrong with the process definition. User (business analytic could be a typical user of jBPM Designer) should not be forced to check server logs. This user very probably doesn't know where is some server log and he should not have access to it.

I also tried to get this incorrect definition into the Designer by pushing to the corresponding repository inside .niogit. I haven't managed to open this definition - this time jBPM Designer did not load at all, so I was not even informed that I should look at a server log.