Recently we changed our serializer and deserializer to Protobuff-net from BinaryFormatter.
In this, I’m facing some problems, after deserializing some of the values are still getting as null.

The Core.Shared library contains two classes – PrimaryKeyObject and TrackingObject

namespace Core.Shared {
[DataContract]
[Serializable]
[ProtoContract]
public class PrimaryKeyObject
{
    [DataMember(Name = "Y1")]
    [ProtoMember(401)]
    internal int? __primaryKeyId;


    [XmlIgnore]
    public int? PrimaryKeyId
    {
        get
        {
            return __primaryKeyId;
        }
    }

    public void SetPrimaryKeyId(int? primaryKeyId)
    {
        __primaryKeyId = primaryKeyId;
    }
} 
}

namespace Core.Shared 
{
[DataContract]
[Serializable]
[ProtoContract]
public class TrackingObject : PrimaryKeyObject 
{
    [DataMember(Name = "Z1")]
    [ProtoMember(301)]
    internal HashSet<string> __propertyChangedList;
    [DataMember(Name = "Z2")]
    [ProtoMember(302)]
    internal EntityStateFlag __entityState;
    [DataMember(Name = "Z3")]
    [ProtoMember(303)]
    public byte[] ROW_VERSION { get; set; }
    [DataMember(Name = "Z4")]
    [ProtoMember(304)]
    internal List<ObservableObject> __removedObjectsFromRelatedLists;
    private bool _changeTrackingDisabled = false;

    public ObservableObject()
        : base()
    {
    }

    public ObservableObject(EntityStateFlag entityState)
    {
        __entityState = entityState;
    }

    [XmlIgnore]
    public EntityStateFlag EntityState
    {
        get
        {
            if (__entityState == 0)
                __entityState = EntityStateFlag.Detached;
            return __entityState;
        }
        set
        {
            if (value != __entityState)
            {
                __entityState = value;
                if ((value == EntityStateFlag.Unchanged || value == EntityStateFlag.Detached) && __propertyChangedList != null)
                    __propertyChangedList = null;
            }
        }
    }
}

[Flags]
public enum EntityStateFlag
{
    Unchanged = 2,
    Added = 4,
    Deleted = 8,
    Modified = 16,
    Detached = 32
}
}

Then we have a Shared library – these classes are usually autogenerated from XML files.
Here as an example, we have a class called – AnsprechpartnerFunktionDetailDC and AbrufauftragUmlagerungEinsatzstoffeITypedDc

namespace Shared 
{
[DataContract]
[Serializable]
[ProtoContract]
public partial class AnsprechpartnerFunktionDetailDC : TrackingObject
{
    public AnsprechpartnerFunktionDetailDC() : base()
    {
    }

    public AnsprechpartnerFunktionDetailDC(EntityStateFlag entityState)
    {
        EntityState = entityState;
    }

    [DataMember(Name = "A1")]
    [ProtoMember(1)]
    internal int __ID_ANSPRECHPARTNER_FUNKTION;
    [XmlIgnore]
    public int ID_ANSPRECHPARTNER_FUNKTION
    {
        get
        {
            return __ID_ANSPRECHPARTNER_FUNKTION;
        }
        set
        {
            if (value != __ID_ANSPRECHPARTNER_FUNKTION)
            {
                __ID_ANSPRECHPARTNER_FUNKTION = value;
                SetPrimaryKeyId(value);
            }
        }
    }
    [DataMember(Name = "A2")]
    [ProtoMember(2)]
    internal string __BEZEICHNUNG;
    [XmlIgnore]
    public string BEZEICHNUNG
    {
        get
        {
            return __BEZEICHNUNG;
        }
        set
        {
            if (value != __BEZEICHNUNG)
            {
                __BEZEICHNUNG = value;
            }
        }
    }
    [DataMember(Name = "A3")]
    [ProtoMember(3)]
    internal bool __AKTIV;
    [XmlIgnore]
    public bool AKTIV
    {
        get
        {
            return __AKTIV;
        }
        set
        {
            if (value != __AKTIV)
            {
                __AKTIV = value;
            }
        }
    }
}
}

namespace Shared
{
[DataContract]
[Serializable]
[ProtoContract]
public partial class AbrufauftragUmlagerungEinsatzstoffeITypedDc : TrackingObject
{
    public AbrufauftragUmlagerungEinsatzstoffeITypedDc() : base()
    {
    }

    public AbrufauftragUmlagerungEinsatzstoffeITypedDc(EntityStateFlag entityState)
    {
        EntityState = entityState;
    }

    [DataMember(Name = "A1")]
    [ProtoMember(11)]
    public int IdMaterial { get; set; }
    [DataMember(Name = "A2")]
    [ProtoMember(12)]
    public decimal? BenotigteMenge { get; set; }
}
}

In another project, we have further processes for the creation of data, serialization, and deserialization.

    static void Main(string[] args)
{
    RegisterTypesForObject();

    Console.WriteLine("Hello, World!");
    MemoryStream objectSerializer = new MemoryStream();
    objectSerializer.Seek(0, SeekOrigin.Begin);

    var x1 = new AbrufauftragUmlagerungEinsatzstoffeITypedDc(EntityModel.Shared.EntityStateFlag.Added)
    {
        IdMaterial = 101,
        BenotigteMenge = 102,
        ROW_VERSION = new byte[] { 0x20, 0x30, 0x40, 0x50, 0x60, 0x70, 0x80 }
    };
    WriteNext(objectSerializer, x1);

    var x2 = new AnsprechpartnerFunktionDetailDC(EntityModel.Shared.EntityStateFlag.Added)
    {
        ID_ANSPRECHPARTNER_FUNKTION = 111,
        AKTIV = true,
        BEZEICHNUNG = "sample test",
        ROW_VERSION = new byte[] { 0x20, 0x30, 0x40, 0x50, 0x60, 0x70, 0x80 }
    };
    WriteNext(objectSerializer, x2);

    objectSerializer.Seek(0, SeekOrigin.Begin);
    var i1 = DeSerialized<AbrufauftragUmlagerungEinsatzstoffeITypedDc>(objectSerializer);
    var i2 = DeSerialized<AnsprechpartnerFunktionDetailDC>(objectSerializer);
}



static readonly Dictionary<int, Type> typeLookup = new Dictionary<int, Type>();
static void WriteNext(Stream stream, object obj)
{
    Type type = obj.GetType();
    if (!typeLookup.ContainsValue(type))
    {
        var key = typeLookup.Count > 0 ? typeLookup.Max(i => i.Key) : 0;
        typeLookup.Add(key + 1, type);

        int field = typeLookup.Single(pair => pair.Value == type).Key;
        Serializer.NonGeneric.SerializeWithLengthPrefix(stream, obj, PrefixStyle.Base128, field);
    }
}

static T DeSerialized<T>(Stream stream)
{
    object obj;
    if (Serializer.NonGeneric.TryDeserializeWithLengthPrefix(stream, PrefixStyle.Base128, field => typeLookup[field], out obj))
    {
        if (obj.GetType() == typeof(T))
            return (T)obj;
    }
    return default(T);
}


public static void RegisterTypesForObject()
{
    var assemblyLocation = System.IO.Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location);
    Assembly assembly = Assembly.LoadFile(assemblyLocation + @"Shared.dll");

    // Specify the target namespace
    string targetNamespace = "Shared";

    // Get all derived classes from the namespace
    var derivedClasses = GetDerivedClassesFromNamespace<ObservableObject>(targetNamespace, assembly);
    int i = 100;
    // Loop through each derived class and output its name
    foreach (var type in derivedClasses)
    {
        if (type == typeof(ObservableObject))
            continue;

        Type currentType = type;
        while (currentType != null && currentType.BaseType != typeof(object))
        {
            RuntimeTypeModel.Default[currentType.BaseType].AddSubType(i, currentType);
            currentType = currentType.BaseType;
            i++;
        }
    }
}

public static IEnumerable<Type> GetDerivedClassesFromNamespace<TBase>(string targetNamespace, Assembly assembly)
{
    var baseType = typeof(TBase);

    return assembly.GetTypes()
                   .Where(t => t.IsClass && !t.IsAbstract &&
                               baseType.IsAssignableFrom(t) &&  // Check if it inherits from the base class
                               t.Namespace == targetNamespace)  // Check if it's in the target namespace
                   .ToList();
}
}

The RegisterTypesForObject method registers its base and derived types at the start of the program the WriteNext Method is used to Serialize and the DeSerialized Method as a deserializer.
After Deserialized of the ‘AnsprechpartnerFunktionDetailDC’ and ‘AbrufauftragUmlagerungEinsatzstoffeITypedDc’ the ROW_VERSION and PrimaryKeyId is null.
(AbrufauftragUmlagerungEinsatzstoffeITypedDc – here currently not used primaryKeyid)

In this case, what did I miss and How can keep ROW_VERSION and PrimaryKeyId values after deserialized?