Fatal error: Uncaught Error: Class "GuzzleHttp\Promise\RejectionException" not found in I:\www\oauth2\auth_server\vendor\guzzlehttp\promises\src\CancellationException.php:8 Stack trace: #0 {main} thrown in I:\www\oauth2\auth_server\vendor\guzzlehttp\promises\src\CancellationException.php on line 8