Camunda bpmn xml file unable to deploy

Question

I started using camunda like yesterday and is following this article (https://medium.com/@klauke.peter/implementing-an-external-task-worker-for-camunda-in-python-566b5ebff488) to poc camunda functionality using python. But on making process diagram in modeler same as mentioned in article and on trying to deploy I am getting error message. Please find both, xml file and error message below.

<?xml version="1.0" encoding="UTF-8"?>
<bpmn:definitions 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" xmlns:di="http://www.omg.org/spec/DD/20100524/DI" xmlns:modeler="http://camunda.org/schema/modeler/1.0" id="Definitions_0lkgql6" targetNamespace="http://bpmn.io/schema/bpmn" exporter="Camunda Modeler" exporterVersion="4.8.1" modeler:executionPlatform="Camunda Platform" modeler:executionPlatformVersion="7.15.0">
  <bpmn:process id="worker1" isExecutable="true">
    <bpmn:startEvent id="StartEvent_1">
      <bpmn:outgoing>Flow_1el6duq</bpmn:outgoing>
    </bpmn:startEvent>
    <bpmn:sequenceFlow id="Flow_1el6duq" sourceRef="StartEvent_1" targetRef="Activity_0vbzulk" />
    <bpmn:serviceTask id="Activity_0vbzulk" name="Generate random number">
      <bpmn:incoming>Flow_1el6duq</bpmn:incoming>
      <bpmn:outgoing>Flow_1g60c66</bpmn:outgoing>
    </bpmn:serviceTask>
    <bpmn:sequenceFlow id="Flow_1g60c66" sourceRef="Activity_0vbzulk" targetRef="Activity_1bckz95" />
    <bpmn:serviceTask id="Activity_1bckz95" name="Print number">
      <bpmn:incoming>Flow_1g60c66</bpmn:incoming>
      <bpmn:outgoing>Flow_0xu9qba</bpmn:outgoing>
    </bpmn:serviceTask>
    <bpmn:endEvent id="Event_031wvih">
      <bpmn:incoming>Flow_0xu9qba</bpmn:incoming>
    </bpmn:endEvent>
    <bpmn:sequenceFlow id="Flow_0xu9qba" sourceRef="Activity_1bckz95" targetRef="Event_031wvih" />
  </bpmn:process>
  <bpmndi:BPMNDiagram id="BPMNDiagram_1">
    <bpmndi:BPMNPlane id="BPMNPlane_1" bpmnElement="worker1">
      <bpmndi:BPMNEdge id="Flow_1el6duq_di" bpmnElement="Flow_1el6duq">
        <di:waypoint x="215" y="117" />
        <di:waypoint x="270" y="117" />
      </bpmndi:BPMNEdge>
      <bpmndi:BPMNEdge id="Flow_1g60c66_di" bpmnElement="Flow_1g60c66">
        <di:waypoint x="370" y="117" />
        <di:waypoint x="430" y="117" />
      </bpmndi:BPMNEdge>
      <bpmndi:BPMNEdge id="Flow_0xu9qba_di" bpmnElement="Flow_0xu9qba">
        <di:waypoint x="530" y="117" />
        <di:waypoint x="592" y="117" />
      </bpmndi:BPMNEdge>
      <bpmndi:BPMNShape id="_BPMNShape_StartEvent_2" bpmnElement="StartEvent_1">
        <dc:Bounds x="179" y="99" width="36" height="36" />
      </bpmndi:BPMNShape>
      <bpmndi:BPMNShape id="Activity_1pp3qeb_di" bpmnElement="Activity_0vbzulk">
        <dc:Bounds x="270" y="77" width="100" height="80" />
      </bpmndi:BPMNShape>
      <bpmndi:BPMNShape id="Activity_0eu99n7_di" bpmnElement="Activity_1bckz95">
        <dc:Bounds x="430" y="77" width="100" height="80" />
      </bpmndi:BPMNShape>
      <bpmndi:BPMNShape id="Event_031wvih_di" bpmnElement="Event_031wvih">
        <dc:Bounds x="592" y="99" width="36" height="36" />
      </bpmndi:BPMNShape>
    </bpmndi:BPMNPlane>
  </bpmndi:BPMNDiagram>
</bpmn:definitions>

Error message

ENGINE-09003 Could not parse 'worker_id1.bpmn'. The markup in the document following the root element must be well-formed. [ deploy-error ]

Answer 1

It is throwing parsing error because have used a service task and did not provide any implementation to it.