Fatal error: Uncaught Error: Interface 'WPMailSMTP\Vendor\Psr\Cache\InvalidArgumentException' not found in C:\wamp64\www\wordpress\wp-content\upgrade-temp-backup\plugins\wp-mail-smtp\vendor_prefixed\google\auth\src\Cache\InvalidArgumentException.php:21 Stack trace: #0 {main} thrown in C:\wamp64\www\wordpress\wp-content\upgrade-temp-backup\plugins\wp-mail-smtp\vendor_prefixed\google\auth\src\Cache\InvalidArgumentException.php on line 21