Fatal error: Uncaught Error: Interface "GuzzleHttp\MessageFormatterInterface" not found in I:\www\oauth2\auth_server\vendor\guzzlehttp\guzzle\src\MessageFormatter.php:38 Stack trace: #0 {main} thrown in I:\www\oauth2\auth_server\vendor\guzzlehttp\guzzle\src\MessageFormatter.php on line 38