收款单接口为什么收款用途老提示必填项

我们要和客户做个收款单接口，版本是6.0，下面是json，但是我 收款用途已经给了 \"FPURPOSEID\": { \"FNumber\": \"SFKYT07_SYS\"},还是提示收款用途是必填字段，就是同步不过去，测试了好多都不行。 {
\"Creator\": \"String\",
\"NeedUpDateFields\": [

],
\"MODEL\": {
\"FRECAMOUNT_E\": \"1\",
\"FRECAMOUNTFOR_E\": \"1000\",
\"FRECTOTALAMOUNT\": \"1000\",
\"FSETTLERECAMOUNTFOR\": \"1000\",
\"FRECTOTALAMOUNTFOR\": \"1000\",
\"FREALRECAMOUNTFOR_D\": \"1000\",
\"FREALRECAMOUNT_D\": \"1\",
\"FPayPurse\": \"SFKYT07_SYS\",
\"FREALRECAMOUNT\": \"1000\",
\"FPLANRECAMOUNT\": \"1000\",
\"FSRCBILLNO\": \"1239812398\",
\"FSRCBILLTYPEID\": \"LZHYSHT_SYS01\",
\"FSRCSETTLETYPEID\": \"JSFS04_SYS\",
\"FAFTTAXTOTALAMOUNT\": \"1000\",
\"FContractType\": {
\"FNUMBER\": \"JSFS04_SYS\"
},
\"FContractType\": {
\"FNUMBER\": \"01\"
},
\"FCURRENCYID\": {
\"FNUMBER\": \"PRE001\"
},
\"FRECEIVEAMOUNTFOR_H\": \"1000\",
\"FEXCHANGETYPE\": \"HLTX01_SYS\",
\"FRECEIVEAMOUNT_H\": \"1000\",
\"FEXCHANGERATE\": \"1\",
\"FSETTLEORGID\": \"101.2\",
\"FPAYORGID\": {
\"FNUMBER\": \"101.2\"
},
\"FSETTLEORGID\": {
\"FNUMBER\": \"101.2\"
},
\"FSETTLERATE\": \"1\",
\"FSETTLECUR\": \"PRE001\",
\"FREALRECAMOUNTFOR\": \"1000\",
\"FBillTypeID\": {
\"FNUMBER\": \"SKDLX02_SYS\"
},
\"FPAYUNITTYPE\": \"BD_Empinfo\",
\"FCONTACTUNIT\": {
\"FNUMBER\": \"20140822\"
},
\"FPAYUNIT\": {
\"FNUMBER\": \"20140822\"
},
\"FCONTACTUNITTYPE\": \"BD_Empinfo\",
\"FReceivableProjectsYC\": \"01\",
\"FID\": 0,
\"AR_RECEIVEBILL__FRECEIVEBILLENTRY\": [
{
\"FSETTLETYPEID\": {
\"FNumber\": \"JSFS01_SYS\"
},
\"FPURPOSEID\": {
\"FNumber\": \"SFKYT07_SYS\"
},
\"FReceivableProjectsYC\": {
\"FNumber\": \"01\"
},
\"FRECTOTALAMOUNTFOR\": \"10000\",
\"FREALRECAMOUNTFOR_D\": \"10000\",
\"FACCOUNTID\": : {
\"FNumber\": \"110060667018010066672\"
}
],
\"FBillNo\": \"12389219ssss\"
}
}