Fatal error: 2.7 upgrade

Fatal error: Call to undefined function: wp_clone() in /home/www/emergencymoneysolutions.info/wp-includes/cache.php on line 380

The Site is currently undergoing maintenance, Sorry for the inconvinience

Any suggestions Im not really all that technically gifted to know what to do.

I tried to do auto upgrade, got to get latest version, and it “restarted going through the whole process and then stopped. Now what do i do? I did a backup earlier/didnt download it or anything, never have, dont know how etc etc as i said im not technical.

I dont really want to lose this site and am a little scared what to do next.

Thanks
Matt