Hi @trivialis,
Were you able to solve the problem? That thread is very old and the bug in it has be fixed. I would not expect you to have the same issue that is listed in that thread.
Unauthorized errors can happen for many reasons, and they are generally ambiguous because they are client facing.
Let me know if you are still running into the error and I can help (if so, please post the full error with message, and any other relevant info you can provide).