Fatal error: Uncaught ErrorException: http_response_code(): Cannot set response code - headers already sent (output started at /var/www/html/includes/header.php:121) in /var/www/html/error_handler.php:3 Stack trace: #0 [internal function]: {closure:/var/www/html/error_handler.php:8}() #1 /var/www/html/error_handler.php(3): http_response_code() #2 [internal function]: {closure:/var/www/html/error_handler.php:2}() #3 {main} thrown in /var/www/html/error_handler.php on line 3