Warning: require(./vendor/autoload.php): failed to open stream: No such file or directory in /home/dklein/public_html/en/404.php on line 4

Fatal error: require(): Failed opening required './vendor/autoload.php' (include_path='.:/opt/alt/php56/usr/share/pear:/opt/alt/php56/usr/share/php') in /home/dklein/public_html/en/404.php on line 4