Warning: require_once(config_files/config.php): failed to open stream: No such file or directory in /htdocs/public/www/index.php on line 3

Fatal error: require_once(): Failed opening required 'config_files/config.php' (include_path='.:/usr/share/php:/usr/share/pear') in /htdocs/public/www/index.php on line 3