Please add cast check (about line №1480 in CopyPaste.cs)

var lights = entity as AdvancedChristmasLights;
if (lights != null)
{
	if (data.ContainsKey("points"))
	{
		foreach (Dictionary<string, object> point in data["points"] as List<object>)
		{
			if (!(point["normal"] is Vector3))
			{
				continue;
			}
			if (!(point["point"] is Vector3))
			{
				continue;
			}
			var _vector = (Vector3)point["normal"];
			var _point = (Vector3)point["point"];
			lights.points.Add(new AdvancedChristmasLights.pointEntry
				{ normal = _vector, point = _point });
		}
	}

	if (data.ContainsKey("animationStyle"))
	{
		lights.animationStyle = (AdvancedChristmasLights.AnimationType)data["animationStyle"];
	}
}