Error validating BPMN import on another BPMN2.0 compliant modeler or viewer
I was able to reproduce this by export 2 BPMN diagram from bizagi modeler. The first one has milestones in the diagram, the second one with the milestones removed.
When importing both diagrams in another BPMN modeler or validating them in something like businessprocessincubator, the one that has the milestones failed with error complaining about some form of unicode characters "&#". I was under the impression that since milestones are not supported by BPMN 2.0, the exported BPMN file will not contain them. But I believe there's a bug with that exclusion.