activiti7 启动流程时，对应assingee为空

问题遇到的现象和发生背景

activit 7

问题相关代码，请勿粘贴截图

//        1. 获取流程引擎
        ProcessEngine defaultProcessEngine = ProcessEngines.getDefaultProcessEngine();
//        2. 通过TaskService 查询任务
        TaskService taskService = defaultProcessEngine.getTaskService();
//        3. 根据 流程的 key 和 任务的负责人查询任务
        List<Task> tasks = taskService.createTaskQuery().processDefinitionKey("myEvention").list();
//                .taskAssignee("zhangsan").list();
//        4. 展示
        tasks.forEach(e -> {
            System.out.println("流程实例 ID -> " + e.getProcessInstanceId());
            System.out.println("任务 ID -> " + e.getId());
            System.out.println("任务负责人 -> " + e.getAssignee());
            System.out.println("任务名称 -> " + e.getName());
        });

对应的bpmn文件

<bpmn:userTask id="Task_13j14ta" name="创建出差申请" camunda:assignee="zhangsan" camunda:candidateUsers="zhangsan">
      <bpmn:incoming>SequenceFlow_1s9xwpt</bpmn:incoming>
      <bpmn:outgoing>SequenceFlow_1jew1sj</bpmn:outgoing>
    </bpmn:userTask>
    <bpmn:userTask id="Task_0cu19v2" name="经理审批" camunda:assignee="lisi" camunda:candidateUsers="lisi">
      <bpmn:incoming>SequenceFlow_1jew1sj</bpmn:incoming>
      <bpmn:outgoing>SequenceFlow_0rcro0v</bpmn:outgoing>
    </bpmn:userTask>
    <bpmn:userTask id="Task_178czq5" name="总经理审批" camunda:assignee="wangwu" camunda:candidateUsers="wangwu">
      <bpmn:incoming>SequenceFlow_0rcro0v</bpmn:incoming>
      <bpmn:outgoing>SequenceFlow_01kx4bh</bpmn:outgoing>
    </bpmn:userTask>
    <bpmn:userTask id="Task_0fcwsrt" name="财务审批" camunda:assignee="zhaoliu" camunda:candidateUsers="zhaoliu">
      <bpmn:incoming>SequenceFlow_01kx4bh</bpmn:incoming>
      <bpmn:outgoing>SequenceFlow_1wx8lyc</bpmn:outgoing>
    </bpmn:userTask>
  </bpmn:process>

运行结果及报错内容

直接使用Camunda Modeler 创建生成的bpmn文件时，activiti 兼容有问题 。
解决办法嘛！！！ 看这个
代码地址: https://gitee.com/SweetLei/activiti-bpmn-tool.git