Problem
You get an Invalid Client error trying to generate a token.
Solution
To successfully generate an OAuth token, the token issuer server must be configured with the client information provided in the token generation request. You can get around this by logging into the Authorization server to verify that the client is correctly configured. For client’s using the Resource Owner OAuth flow, a client secret must be configured and supplied in the token request. For clients using the Implicit OAuth flow, the relevant redirect URLs must be configured.
You can see further details of this error by turning on logging.