Newtonsoft.Json TypeNameHandling problem. Linqpad cannot find a custom class assembly

I have this code

void Main()
{
    var points = new Point[5];
    var rnd = new Random();
    for (int i = 0; i < points.Length; i++)
    {
        points[i] = rnd.Next(3) % 2 == 0 ? new Point() : new Point3D();
        points[i].GetType().Dump();
    }
    var settings = new JsonSerializerSettings
    {
        TypeNameHandling = TypeNameHandling.Auto
    };
    string json = JsonConvert.SerializeObject(points, Newtonsoft.Json.Formatting.Indented,settings);

    points = JsonConvert.DeserializeObject<Point[]>(json, settings);
}

public class Point3D : Point
{
    public int Z { get; private set;}
    public Point3D() : base()
    {
        var rnd = new Random();
        Z = rnd.Next(10);
    }
    [JsonConstructor]
    public Point3D(int X, int Y, int Z) : base(X, Y)
    {
        this.Z = Z;
    }
}
public class Point
{
    public int X { get; private set; }
    public int Y { get; private set; }

    public Point() { }
    [JsonConstructor]
    public Point(int X, int Y)
    {
        this.X = X;
        this.Y = Y;
    }
}

everything is working fine, I can serialize points object, but when I try to deserialize (the last line of code) I get this error message

JsonSerializationException: Error resolving type specified in JSON 'UserQuery+Point3D, LINQPadQuery'. Path '[0].$type', line 3, position 46.
Could not load file or assembly 'LINQPadQuery, Culture=neutral, PublicKeyToken=null'. Operation is not supported. (0x80131515)

this happens only if I have Point3D objects in my array. If array consists from only Point objects, everything is fine. Before the last version of Linqpad, the code like this worked properly. I think that Linqpad cannot find a custom class for the reflection.