webapi导入业务员报职员是必录项，请老师解答

{
"Creator": "",
"NeedUpDateFields": [],
"Model": {
"FOperatorId": 0,
"FOperatorType": "XSY",
"BD_OPERATOR__FEntity": [
{
"FOperatorType_ETY": "XSY",
"FBizOrgId": {
"FNumber": 100
},
"FStaffId": {
"FID": 0,
"FStaffNumber": "5214395357056908416"
},
"FIsUser": "true"
}
]
}
}

提交以上JSON到BD_OPERATOR，5214395357056908416这个是职员编码，且已审核，岗位信息一切正常，手工是可以选择并保存到业务员里的。但WEBAPI导入报以下错误：
{
"Result": {
"ResponseStatus": {
"ErrorCode": 500,
"IsSuccess": false,
"Errors": [
{
"FieldName": "FStaffId",
"Message": "单据体“业务员分录”第1行字段“职员”是必填项"
},
{
"FieldName": "AbstractInteractionResult",
"Message": "AbstractInteractionResult.InteractionContext is null"
}
]
},
"Id": ""
}

}
请老师解答！多谢