getting error when going to wordpress site

Hi,
I'm getting this error when trying to go to a client site:
Warning: require(/home/bnmpro5/public_html/baincil/wp-includes/rest-api/fields/class-wp-rest-meta-fields.php): failed to open stream: No such file or directory in /home/bnmpro5/public_html/baincil/wp-settings.php on line 238

Fatal error: require(): Failed opening required '/home/bnmpro5/public_html/baincil/wp-includes/rest-api/fields/class-wp-rest-meta-fields.php' (include_path='.:disappointed:opt/cpanel/ea-php56/root/usr/share/pear') in /home/bnmpro5/public_html/baincil/wp-settings.php on line 238