字段“往来单位”是必填项" 字段 求解答！！！！

{"Result":{"ResponseStatus":{"ErrorCode":500,"IsSuccess":false,"Errors":[{"FieldName":"FCONTACTUNIT","Message":"字段“往来单位”是必填项","DIndex":0},{"FieldName":"FPAYUNIT","Message":"字段“付款单位”是必填项","DIndex":0}],"SuccessEntitys":[],"SuccessMessages":[],"MsgCode":0},"Id":"","NeedReturnData":[{}]}}

往来单位 付款单位 json字符串都添加了 ，仍然报错 如上。

{
"Model": {
"FCONTACTUNITTYPE": "客户",
"FDOCUMENTSTATUS": "A",
"FRECEIVEBILLENTRY": [{
"FPOSTDATE": "2018-10-18",
"FRECTOTALAMOUNTFOR": 100,
"FPURPOSEID": {
"FNumber": "SFKYT01_SYS"
},
"FREALRECAMOUNTFOR_D": 100,
"FSETTLETYPEID": {
"FNumber": "JSFS01_SYS"
}
}],
"FBUSINESSTYPE": "销售业务",
"FSETTLECUR": {
"FNumber": "PRE001"
},
"FDATE": "2018-10-18",
"FCURRENCYID": {
"FNumber": "PRE001"
},
"FPAYORGID": {
"FNumber": "100"
},
"FCONTACTUNIT": {
"FNumber": "CUST0002"
},
"FPAYUNIT": {
"FNumber": "CUST0002"
},
"FCancelStatus": "B",
"FBillTypeID": {
"FNumber": "SKDLX01_SYS"
},
"FPAYUNITTYPE": "客户"
},
"Creator": "110"
}