This is a bug in the auto-generated code! Somehow some old code has sneaked through. The first solution given here is indeed right, there is no @original_playerid, and so you can safely change it to @PlayerId. There is no need to add a ControlParameter. I believe Dave Sussman is at this moment reworking the chapter for the C# version and he will add some more to this thread (as well as making sure it's corrected in the code) about this matter.