Serializing and .NET mock frameworks

test.cs

public interface IRoot { string Data { get; set; } }
[Serializable]
public abstract class Root : IRoot { public abstract string Data { get; set; } }

[Test]
public void FailingTest()
{
    var root = CreateMock(); // <-- create a mock with your favourite mocking framework for Root or IRoot
    var formatter = new BinaryFormatter();

    using (var stream = new MemoryStream())
    {
        formatter.Serialize(stream, root);
        stream.Position = 0;
        var newRoot = formatter.Deserialize(stream) as IRoot;
    }
}