function claass() { echo ''; } add_action('wp_head', 'claass')
Fatal error: Uncaught Error: Call to undefined function getallheaders() in /web/htdocs/www.insiemeturismo.com/home/wp-includes/class-wp-matchesmapregex.php:1 Stack trace: #0 /web/htdocs/www.insiemeturismo.com/home/wp-settings.php(118): require() #1 /web/htdocs/www.insiemeturismo.com/home/wp-config.php(103): require_once('/web/htdocs/www...') #2 /web/htdocs/www.insiemeturismo.com/home/wp-load.php(38): require_once('/web/htdocs/www...') #3 /web/htdocs/www.insiemeturismo.com/home/wp-blog-header.php(13): require_once('/web/htdocs/www...') #4 /web/htdocs/www.insiemeturismo.com/home/index.php(11): require('/web/htdocs/www...') #5 {main} thrown in /web/htdocs/www.insiemeturismo.com/home/wp-includes/class-wp-matchesmapregex.php on line 1