3.1.5.2.1.3 Processing Details
The steps performed by the OAuth 2.0 client to request an access token are defined in [RFC6749] section 4.1.3 (Access Token Request).
Additionally, the OAuth 2.0 client MUST expect the AD FS server to respond with an error response according to the requirements of [RFC6749] section 5.2 (Error Response) with the error parameter of the response set to the server_error error code (defined in section 2.2.4.2).