Getting INTERNAL error on creating order

(previous post deleted for update)

edit:

I don’t use C# so I can’t test your code (although I know some C), but looking at it nothing is jumping out to me as wrong, I’m sure I’m just not seeing the problem though.

I have working python code here that you might be able to use to help debug your problem. Hopefully it helps. If not you can post more info and I’ll try to help.