Wordpress网站返回致命错误“无法重新声明wp_get_server_protocol()(之前在/ home / ...中声明”

I have a wordpress site which is returning the following

Fatal error: Cannot redeclare wp_get_server_protocol() (previously declared in /home/wryl/public_html/wp-includes/load.php:16) in /home/wryl/public_html/wp-includes/load.php on line 21

It's not a site i have anything to do with normally but have been asked if i can fix this issue. I've attempted to re-upload clean wordpress files (wp-admin & wp-includes) and made sure all the permissions have been set correctly but still get the above error. I'm a little lost as to what to try next