webapi保存数据报错"HelpLink":null,"Message

{
"Creator": "Y1660",
"NeedUpDateFields": "",
"Model": {
"FID": 0,
"FBillType": "2",
"FEntity": [
{
"FEntryID": 0,
"F_SourceBillType": "PABR_FA_ASSET",
"F_SourceBillNo": "A201704050001",
"F_ASSET_NUM": " ",
"F_SECOND_NO": "CK-H-001",
"F_ASSET_NAME": "周转车",
"F_MODEL": "1.0×105Ω≤Rg＜1.0×109Ω （点到接地点）",
"F_MAC_NO": " ",
"F_JianDing_Date": "\/Date(1491910063607+0800)\/",
"F_CertNum": "",
"F_COST_CENTER": {
"FNumber": "103098"
},
"F_Supplier": {
"FNumber": ""
},
"F_CHECK_TYPE": "B",
"F_OK_NG": "OK",
"F_SendOrLive": "1",
"F_Remark": "PDA扫描"
}
]
}
}

Fidder web debugger监控到如下错误提示：
{
"format": 1,
"useragent": "ApiClient",
"rid": "-1799699728",
"parameters": "[\"PABR_FA_AssetRegulate\",{\"Creator\":\"Y1660\",\"NeedUpDateFields\":\"\",\"Model\":{\"FID\":0,\"FBillType\":\"2\",\"FEntity\":[{\"FEntryID\":0,\"F_SourceBillType\":\"PABR_FA_ASSET\",\"F_SourceBillNo\":\"A201704050001\",\"F_ASSET_NUM\":\" \",\"F_SECOND_NO\":\"CK-H-001\",\"F_ASSET_NAME\":\"周转车\",\"F_MODEL\":\"1.0×105Ω≤Rg＜1.0×109Ω （点到接地点）\",\"F_MAC_NO\":\" \",\"F_JianDing_Date\":\"\\/Date(1491910063607+0800)\\/\",\"F_CertNum\":\"\",\"F_COST_CENTER\":{\"FNumber\":\"103098\"},\"F_Supplier\":{\"FNumber\":\"\"},\"F_CHECK_TYPE\":\"B\",\"F_OK_NG\":\"OK\",\"F_SendOrLive\":\"1\",\"F_Remark\":\"PDA扫描\"}]}}]",
"timestamp": "\/Date(1491910155607+0800)\/",
"v": "1.0"
}

response_error:{"InnerExWrapper":{"IsEmpty":false,"Data":{},"HelpLink":null,"Message":"调用的目标发生了异常。","Source":null,"StackTrace":" 在 System.RuntimeMethodHandle.InvokeMethod(Object target, Object[] arguments, Signature sig, Boolean constructor)\r\n 在 System.Reflection.RuntimeMethodInfo.UnsafeInvokeInternal(Object obj, Object[] parameters, Object[] arguments)\r\n 在 System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)\r\n 在 Kingdee.BOS.ServiceFacade.KDServiceFx.ServiceExecutor.Execute(KDServiceContext context, ServiceType svcType, String[] paraValues, SerializerProxy serializeProxy, ServiceType beginMethod)","TargetSite":null,"ExceptionType":"System.Reflection.TargetInvocationException, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089","InnerException":{"IsEmpty":false,"Data":{},"HelpLink":null,"Message":"{ctx == null}","Source":null,"StackTrace":" 在 Kingdee.BOS.Contracts.ServiceFactory.GetService[T](Context ctx)\r\n 在 Kingdee.BOS.ServiceHelper.MetaDataServiceHelper.Load(Context ctx, String id, String layoutViewId, Boolean bRuntime)\r\n 在 Kingdee.BOS.WebApi.FormService.WebApiServiceCall.ExcuteSpecialOperation(Context ctx, String formId, String data, Int64 opId)\r\n 在 Kingdee.BOS.WebApi.ServicesStub.DynamicFormService.Save(String formid, String data)","TargetSite":null,"ExceptionType":"System.Exception, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089","InnerException":null}},"ClassName":"Kingdee.BOS.ServiceFacade.ServiceException","Message":"{ctx == null}","Data":null,"InnerException":null,"HelpURL":null,"StackTraceString":" 在 Kingdee.BOS.ServiceFacade.KDServiceFx.ServiceExecutor.Execute(KDServiceContext context, ServiceType svcType, String[] paraValues, SerializerProxy serializeProxy, ServiceType beginMethod)\r\n 在 Kingdee.BOS.ServiceFacade.KDServiceFx.ExecuteServiceModule.OnProcess(KDServiceContext context)\r\n 在 Kingdee.BOS.ServiceFacade.KDServiceFx.ModulePipeline.ExcuteRequest(KDServiceContext context)\r\n 在 Kingdee.BOS.ServiceFacade.KDServiceFx.RequestExcuteRuntime.BeginRquest(RequestExtractor requestExtractor, WebContext webCtx)\r\n 在 Kingdee.BOS.ServiceFacade.KDServiceFx.RequestExcuteRuntime.StartRequest(RequestExtractor requestExtractor, WebContext context)\r\n 在 Kingdee.BOS.ServiceFacade.KDServiceFx.KDSVCHandler.ExecuteRequest(WebContext ctx, RequestExtractor requestExtractor)\r\n 在 Kingdee.BOS.ServiceFacade.KDServiceFx.KDSVCHandler.ProcessRequestInternal(WebContext webCtx, RequestExtractor requestExtractor)","RemoteStackTraceString":null,"RemoteStackIndex":0,"ExceptionMethod":"8\nExecute\nKingdee.BOS.ServiceFacade.KDServiceFx, Version=6.0.413.1, Culture=neutral, PublicKeyToken=null\nKingdee.BOS.ServiceFacade.KDServiceFx.ServiceExecutor\nSystem.String Execute(Kingdee.BOS.ServiceFacade.KDServiceFx.KDServiceContext, Kingdee.BOS.ServiceFacade.KDServiceFx.ServiceType, System.String[], Kingdee.BOS.ServiceFacade.SerializerProxy, Kingdee.BOS.ServiceFacade.KDServiceFx.ServiceType)","HResult":-2147467259,"Source":"Kingdee.BOS.ServiceFacade.KDServiceFx","WatsonBuckets":null,"_httpCode":500}

我把传入的JSON校验了 是正确的