Fatal error: Uncaught Error: Class "mysqli" not found in /var/www/html/db_open.php:29 Stack trace: #0 /var/www/html/header.php(16): require_once() #1 /var/www/html/index.php(6): require_once('/var/www/html/h...') #2 {main} thrown in /var/www/html/db_open.php on line 29