invalid_request | A required field is missing, malformed, or inconsistent. | Correct the request; do not retry unchanged. |
invalid_client | Client authentication failed or the client is inactive. | Verify the client ID and current secret, or use the configured public-client flow. |
invalid_grant | A code or refresh token is expired, consumed, reused, revoked, or bound to different request data. | Start a new authorization. |
unsupported_grant_type | The token request used an unsupported grant. | Use authorization_code or refresh_token. |
access_denied | The user declined authorization. | Return the user to your application without creating a connection. |