Fatal error: Uncaught Error: Class 'WPMailSMTP\MigrationAbstract' not found in /home/ursatac/public_html/wp-content/plugins/wp-mail-smtp-pro/src/Pro/Migration.php:13 Stack trace: #0 {main} thrown in /home/ursatac/public_html/wp-content/plugins/wp-mail-smtp-pro/src/Pro/Migration.php on line 13