Fatal error: Uncaught Error: Interface "GuzzleHttp\Promise\PromiseInterface" not found in /home/customer/www/londonfencingclub.co.uk/public_html/vendor/guzzlehttp/promises/src/Promise.php:9 Stack trace: #0 {main} thrown in /home/customer/www/londonfencingclub.co.uk/public_html/vendor/guzzlehttp/promises/src/Promise.php on line 9