Can not implement discriminated union and serialize it - serialization

Question

Hello i am trying to create a hierarchy of classes using a discriminated unionand it seems i can't serialize them.I keep getting this error :
Newtonsoft.Json.JsonSerializationException: 'Self referencing loop detected for property 'AsRun' with type 'MsgPattern.Message+Run'. Path ''.'
Base class
[Serializable]
public abstract partial class Message {
public enum Type {
WALK = 0,
RUN = 1
}
protected abstract Type Discriminator { get; }
public Type Kind => this.Discriminator;
internal static Message Create(string data) {
var message = JsonConvert.DeserializeObject<Message>(data);
switch (message.Kind) {
case Type.RUN:message= message.AsRun;break;
case Type.WALK:message= message.AsWalk;break;
}
return message;
}
[JsonIgnore]
public bool IsWalk => this.Kind==Type.Walk;
[JsonIgnore]
public bool IsRun => this.Kind==Type.Run;
[JsonIgnore]
public Message.Walk AsWalk => this as Message.Walk;
[JsonIgnore]
public Message.Run AsRun => this as Message.Run;
}
Dervived
partial class Message {
public class Run : Message {
protected override Type Discriminator => Type.RUN;
public string Location { get; set; }
public int Speed { get; set; }
}
}
partial class Message {
public class Walk : Message {
protected override Type Discriminator => Type.WALK;
public int Gait { get; set; }
public bool IsJogging { get; set; }
}
}
Usage
class Program {
static void Main(string[] args) {
Message.Run run = new Message.Run { Location = "asa", Speed = 33 };
string data = JsonConvert.SerializeObject(run);
Message msg=Message.Create(data);
}
}
I will get these type of messages via json and i want to be able to do actions based on their type. I do not understand why i can't serialize them .
P.S I know it's a self-referencing loop but I need those As[something] and Is[Something] fields.