C# Soap XML SerializationException при синтаксическом анализе объекта

Когда я пытаюсь разобрать мыло xml на объекты, я получаю исключение ниже, не уверен, что я делаю не так.

Исключение:

An unhandled exception of type 'System.Runtime.Serialization.SerializationException' occurred in System.Runtime.Serialization.dll

Additional information: Error in line 1 position 687. Element 'http://soap.sforce.com/2005/09/outbound:sObject' contains data from a type that maps to the name 'urn:sobject.enterprise.soap.sforce.com:Contact'. The deserializer has no knowledge of any type that maps to this name. Consider using a DataContractResolver if you are using DataContractSerializer or add the type corresponding to 'Contact' to the list of known types - for example, by using the KnownTypeAttribute attribute or by adding it to the list of known types passed to the serializer.

 static void Main(string[] args)
    {

        string inputString = "<?xml version=\"1.0\" encoding=\"UTF - 8\"?> <soapenv:Envelope xmlns:soapenv=\"http://schemas.xmlsoap.org/soap/envelope/\" xmlns:xsd=\"http://www.w3.org/2001/XMLSchema\" xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\"> <soapenv:Body> <notifications xmlns=\"http://soap.sforce.com/2005/09/outbound\"> <SessionId xsi:nil=\"true\"/> <EnterpriseUrl>https://hultibs--FullDev.cs10.my.salesforce.com/services/Soap/c/44.0/00DJ0000003QX7f</EnterpriseUrl> <PartnerUrl>https://hultibs--FullDev.cs10.my.salesforce.com/services/Soap/u/44.0/00DJ0000003QX7f</PartnerUrl> <Notification> <Id>04lJ000000PoRS2IAN</Id> <sObject xsi:type=\"sf:Contact\" xmlns:sf=\"urn:sobject.enterprise.soap.sforce.com\"> <sf:Id>0033600001koT9qAAE</sf:Id> <sf:Email>[email protected]</sf:Email> <sf:Student_ID__c>5192435</sf:Student_ID__c> </sObject> </Notification> </notifications> </soapenv:Body> </soapenv:Envelope>";


        FromXml(inputString);
        Console.ReadLine();
    }

 public static void FromXml(string Xml)
    {
        using (var reader = XmlReader.Create(new StringReader(Xml)))
        {
            Message m = Message.CreateMessage(reader, int.MaxValue, MessageVersion.Soap11);
            var body = m.GetBody<Notifications>();
            Console.WriteLine(body);
        }

    }
[DataContract(Name = "sObject", Namespace = "http://soap.sforce.com/2005/09/outbound")]
    public class SObject
    {
        [DataMember(Name = "Id", Order = 1)]
        public string Id { get; set; }
        [DataMember(Name = "Email", Order = 2)]
        public string Email { get; set; }
        [DataMember(Name = "Student_ID__c", Order = 3)]
        public string Student_ID__c { get; set; }
        [DataMember(Name = "type", Order = 4)]
        public string Type { get; set; }
        [DataMember(Name = "sf", Order = 5)]
        public string Sf { get; set; }
    }

    [DataContract(Name = "Notification", Namespace = "http://soap.sforce.com/2005/09/outbound")]
    public class Notification
    {
        [DataMember(Name = "Id", Order = 1)]
        public string Id { get; set; }
        [DataMember(Name = "sObject", Order = 2)]
        public SObject SObject { get; set; }
    }

    [DataContract(Name = "notifications", Namespace = "http://soap.sforce.com/2005/09/outbound")]
    public class Notifications
    {

        [DataMember(Name = "ActionId", Order = 2)]
        public string ActionId { get; set; }
        [DataMember(Name = "EnterpriseUrl", Order = 3)]
        public string EnterpriseUrl { get; set; }
        [DataMember(Name = "PartnerUrl", Order = 4)]
        public string PartnerUrl { get; set; }
        [DataMember(Name = "Notification", Order = 5)]
        public Notification Notification { get; set; }
    }