Fatal error: Uncaught Error: Interface 'WPMailSMTP\Vendor\GuzzleHttp\Promise\PromisorInterface' not found in C:\wamp64\www\wordpress\wp-content\upgrade-temp-backup\plugins\wp-mail-smtp\vendor_prefixed\guzzlehttp\guzzle\src\Pool.php:23 Stack trace: #0 {main} thrown in C:\wamp64\www\wordpress\wp-content\upgrade-temp-backup\plugins\wp-mail-smtp\vendor_prefixed\guzzlehttp\guzzle\src\Pool.php on line 23