failed to open stream: No such file or directory

What is this ? and how can it will solve.. help me ..

This is not opening….. Issues comes when i a

Warning: require(/home/mcdc74np/public_html/wp-includes/user.php): failed to open stream: No such file or directory in /home/mcdc74np/public_html/wp-settings.php on line 121

Fatal error: require(): Failed opening required '/home/mcdc74np/public_html/wp-includes/user.php' (include_path='.:/opt/php54/lib/php') in /home/mcdc74np/public_html/wp-settings.php on line 121