折腾了好几遍一直提示：VM81:1 Error: errCode: -404011 cloud function execution error | errMsg: cloud.callFunction:fail requestID 53d8b83f-d8f8-11e9-b940-525400dee61a, cloud function service error code -504002, error message errCode: -1 unknown error | errMsg: parameter.data should be object instead of undefined;; at cloud.callFunction api; 

求助，各位大神！！谢谢！

云服务器代码

// 云函数入口文件

const cloud = require('wx-server-sdk')

cloud.init()

const db = cloud.database()

const Balancesconn = db.collection('Parea')

exports.main=async(event,context)=>{

return await Balancesconn.add({

Pareacode: "1811893",

Pareaname: "秦淮区"

})

}

云客户端代码

const app = getApp()

const db = wx.cloud.database()

const Balancesconn = db.collection('Parea')

var util = require('../../utils/util.js');

Page({

data: {

motto: 'Hello World',

userInfo: {},

cruserInfo:{},

arr:[],

employee: '',

parea: '',

hasUserInfo: false,

canIUse: wx.canIUse('button.open-type.getUserInfo'),

Balancess:[]

},

//事件处理函数

UserAdd: function (e) {

wx.cloud.callFunction({

// 云函数名称

name: 'Balances',

// 传给云函数的参数

})

.then(res => {

console.log(res)

})

.catch(console.error)

}

})