При вызове веб сервиса через анонимный вызов, получаю ошибку в ответе

Request Error
		
The server encountered an error processing the request. The exception message is 'Incoming message for
			operation 'CreateLead' (contract 'LeadService.svc' with namespace 'http://tempuri.org/')
			contains an unrecognized http body format value 'Json'. The expected body format value is 'Raw'. This can be
			because a WebContentTypeMapper has not been configured on the binding. See the documentation of
			WebContentTypeMapper for more details.'. See server logs for more details. The exception stack trace is:
		

вызов произвожу с помощью

0/ServiceModel/LeadService.svc/CreateLead

при этом , если вызываю с помощью куки авторизации , то все норм



Сигнатура метода

 

[OperationContract]
		[WebInvoke(Method = "POST", UriTemplate = "CreateLead", BodyStyle = WebMessageBodyStyle.Bare,
		RequestFormat = WebMessageFormat.Json, ResponseFormat = WebMessageFormat.Json)]
		public LeadDataResponse CreateLead(Stream request) {

модель

 

[DataContract]
	public class LeadDataResponse {
		[DataMember]
		public Guid LeadID {
			get;
			set;
		}
		[DataMember]
		public int ResultCode {
			get;
			set;
		}
		[DataMember]
		public string ResultDescription {
			get;
			set;
		}
	}