Fatal error: Uncaught Error: Interface 'WPMailSMTP\Vendor\GuzzleHttp\Promise\PromiseInterface' not found in C:\wamp64\www\wordpress\wp-content\upgrade-temp-backup\plugins\wp-mail-smtp\vendor_prefixed\guzzlehttp\promises\src\FulfilledPromise.php:14 Stack trace: #0 {main} thrown in C:\wamp64\www\wordpress\wp-content\upgrade-temp-backup\plugins\wp-mail-smtp\vendor_prefixed\guzzlehttp\promises\src\FulfilledPromise.php on line 14