- 当前 Bug 的表现（可附上截图）

- 预期表现

- 复现路径

- 提供一个最简复现 Demo

按照

巧借 [ 小程序云开发 ] 快速接入微信支付功能

文进行接入

npm i --product

设定好用户id、key等参数后，接下单，出现以下错误

WAService.js:1 Uncaught (in promise) Error: errCode: -404011 cloud function execution error | errMsg: cloud.callFunction:fail requestID c077ad8b-99a8-11e9-b5ec-525400b2c41b, cloud function service error code -504002, error message Cannot read property 'length' of undefined; at cloud.callFunction api; 

    at new u (WAService.js:1)

    at d (WAService.js:1)

    at Object.t.returnAsFinalCloudSDKError (WAService.js:1)

    at Function.success (WAService.js:1)

    at WAService.js:1

    at C (WAService.js:1)

    at i.<anonymous> (WAService.js:1)

    at i.emit (WAService.js:1)

    at hc (WAService.js:1)

    at WAService.js:1

请问什么原因？