Fatal error: Uncaught Error: Call to undefined function add_filter() in /var/www/clients/client0/web9/web/wp-content/plugins/contact-form-7/includes/special-mail-tags.php:7 Stack trace: #0 {main} thrown in /var/www/clients/client0/web9/web/wp-content/plugins/contact-form-7/includes/special-mail-tags.php on line 7