Fatal error: Uncaught Error: Interface 'GuzzleHttp\Promise\PromiseInterface' not found in C:\inetpub\wwwroot\mantis\vendor\guzzlehttp\promises\src\Promise.php:9 Stack trace: #0 {main} thrown in C:\inetpub\wwwroot\mantis\vendor\guzzlehttp\promises\src\Promise.php on line 9