JSON 错误：（422） 不可处理的实体换行？VB.NET

问：

JSON 请求有问题。我收到“远程服务器返回错误：（422） 无法处理的实体”。返回错误。我逐行浏览了 API 用户指南，只发现了一个异常。我不知道这是否会导致错误。

以下是完整的 JSON 语句：

{"service":{"level":"STD"},"payment":{"terms":"Prepaid","payer":"Third Party"},"transit":{"pickupDate":"20230728"},"commodities":[{"classification":"60","weight":"2600","length":"42","width":"42","height":"45","pieces":"2","packageingType":"PAT","description":"USED BOOKS","stackable":"Y"}],"origin":{"account":"","city":"Knoxville","stateProvince":"TN","postalCode":"37918","country":"USA"},"destination":{"account":"","city":"Atlanta","stateProvince":"GA","postalCode":"30306","country":null},"billTo":{"account":"0627227","name":"FMS","address":"3517 Neil Dr","city":"Knoxvile","stateProvince":"TN","postalCode":"37918","country":"USA"}}

以下是商品的用户指南示例;

这是我发送的内容：

似乎（在我发送的内容中）在“商品”一词之后有一个换行符：[ {

正如 API 示例所示 “”commodities“ ： [ {” 之间没有换行符 “[” 和 “{ ”。

魔术问题 *** 换行会导致错误吗，最重要的是如何摆脱它？ 我对 JSON 非常陌生并且独自工作，因此任何帮助将不胜感激。

将 Load 调暗为新 fgtload

    Dim Item1 As New items

    With Item1
        .classification = ("60")
        .weight = ("2600")
        .length = ("42")
        .width = ("42")
        .height = ("45")
        .pieces = ("2")
        .packageingType = ("PAT")
        .description = ("USED BOOKS")
        .stackable = ("Y")
    End With



    Load.commodities.Add(Item1)


Public Class fgtload 'Primary wrapper
    Public service As New fgtservice
    Public payment As New fgtpayment
    Public transit As New fgttransit
    Public commodities As New List(Of Items)
    Public origin As New fgtorigin
    Public destination As New fgtdestination
    Public billTo As New fgtbillto
End Class

Public Class Items
    Public classification As String 'class  required
    Public weight As String '7max  lbs required
    Public length As String '3max required
    Public width As String '3max required
    Public height As String '3 max required
    Public pieces As String ' 5 max required
    Public packageingType As String 'required  PAT for Pallet , LSE for Loose
    Public description As String 'required
    Public stackable As String 'required
End Class