Fatal error: Uncaught Error: Class "WPMailSMTP\Migrations" not found in /var/www/wp-content/plugins/wp-mail-smtp/src/Core.php:403 Stack trace: #0 /var/www/wp-includes/class-wp-hook.php(324): WPMailSMTP\Core->get_migrations('') #1 /var/www/wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters(NULL, Array) #2 /var/www/wp-includes/plugin.php(517): WP_Hook->do_action(Array) #3 /var/www/wp-settings.php(550): do_action('plugins_loaded') #4 /var/www/wp-config.php(108): require_once('/var/www/wp-set...') #5 /var/www/wp-load.php(50): require_once('/var/www/wp-con...') #6 /var/www/wp-blog-header.php(13): require_once('/var/www/wp-loa...') #7 /var/www/index.php(17): require('/var/www/wp-blo...') #8 {main} thrown in /var/www/wp-content/plugins/wp-mail-smtp/src/Core.php on line 403