The site that example code is on has one issue open. I ran the text of the issue through a translator app and got the following:
I'm not sure, but I think the cloud has a new API. On two different servers, everything worked smoothly until 01-04-2018. I think they changed something there.
Now it is authorized, but the file cannot be downloaded or uploaded.
So, we may need to keep looking. Or, run the API through a translator and test thoroughly.