Setting up OAuth 2.0 - What does this error mean: The client application is not known or is not authorized

This article is part of the article serie Setting up OAuth 2.0 - Introduction

When acquiring the authorization code the following error is shown:

The client application is not known or is not authorized.

This error is shown when the re-direct URL in the GET for acquiring the authorization code is different than the re-direct URL that is registered on the client ID. These URL's should always be the same. This means that the URL need to be changed.

Solution
Change the redirect URL in the GET equal to the registered redirect URL, this can easily be done in the developers portal.

The client ID should not contain more then four re-direct url's (OTAP).