Warning: require(./wp-blog-header.php): Failed to open stream: No such file or directory in /home/.sites/70/site841/web/index.php on line 17

Fatal error: Uncaught Error: Failed opening required './wp-blog-header.php' (include_path='.:/usr/lib/php://share/php/php:/usr/share/pear:/usr/share/php') in /home/.sites/70/site841/web/index.php:17
Stack trace:
#0 {main}
  thrown in /home/.sites/70/site841/web/index.php on line 17