此错误通常是由未定义的变量或对象导致的。检查您的代码，确保所有变量都已声明或初始化。如果问题是对象属性未定义，请确保您的代码正确访问对象属性。以下是一个示例，演示如何正确使用AWS Step Function，并预防此错误的发生。

// Define state machine
const stateMachine = {
  Comment: 'A simple AWS Step Functions state machine example',
  StartAt: 'HelloWorld',
  States: {
    HelloWorld: {
      Type: 'Task',
      Resource: 'arn:aws:lambda:REGION:ACCOUNT_ID:function:FUNCTION_NAME',
      Next: 'CheckResult'
    },
    CheckResult: {
      Type: 'Choice',
      Choices: [
        {
          Variable: '$.status',
          NumericEquals: 200,
          Next: 'Success'
        },
        {
          Variable: '$.status',
          NumericEquals: 400,
          Next: 'Failure'
        },
        {
          Variable: '$.status',
          NumericEquals: 404,
          Next: 'NotFound'
        }
      ],
      Default: 'Failure'
    },
    Success: {
      Type: 'Pass',
      Result: 'Success'
    },
    Failure: {
      Type: 'Pass',
      Result: 'Failure'
    },
    NotFound: {
      Type: 'Pass',
      Result: 'NotFound'
    }
  }
};

// Start state machine execution
const params = {
  stateMachineArn: 'arn:aws:states:REGION:ACCOUNT_ID:stateMachine:STATE_MACHINE_NAME',
  input: '{"key1": "value1", "key2": "value2", "status": 200 }'
};

stepfunctions.startExecution(params, (err, data) => {
  if (err) console.log(err, err.stack);
  else console.log(data);
});