I run the method openDiagram for next diagram:
<?xml version="1.0" encoding="UTF-8"?>
<bpmn:definitions xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:bpmn="http://www.omg.org/spec/BPMN/20100524/MODEL" xmlns:bpmndi="http://www.omg.org/spec/BPMN/20100524/DI" xmlns:dc="http://www.omg.org/spec/DD/20100524/DC" id="Definitions_141dzwv" targetNamespace="http://bpmn.io/schema/bpmn">
<bpmn:collaboration id="Collaboration_171vgzq">
<bpmn:participant id="Participant_1drn3do" processRef="Process_1" />
</bpmn:collaboration>
<bpmn:process id="Process_1" isExecutable="false">
<bpmn:startEvent id="StartEvent_1" />
</bpmn:process>
<bpmndi:BPMNDiagram id="BPMNDiagram_1">
<bpmndi:BPMNPlane id="BPMNPlane_1" bpmnElement="Collaboration_171vgzq">
<bpmndi:BPMNShape id="Participant_1drn3do_di" bpmnElement="Participant_1drn3do">
<dc:Bounds x="123" y="82" width="600" height="250" />
</bpmndi:BPMNShape>
<bpmndi:BPMNShape id="_BPMNShape_StartEvent_2" bpmnElement="StartEvent_1">
<dc:Bounds x="173" y="102" width="36" height="36" />
</bpmndi:BPMNShape>
</bpmndi:BPMNPlane>
</bpmndi:BPMNDiagram>
</bpmn:definitions>
and the method to print the output: unparsable content detected
the image with the error is in topic