login

what went wrong here???
when i try to visit my website it says…

Fatal error: Cannot redeclare get_query_var() (previously declared in /var/www/chokcolorart.dk/public_html/wp-includes/query.php:24) in /var/www/chokcolorart.dk/public_html/wp-includes/post.php on line 28

and it even says the same when i try to login to my site administration

I have deactivated all my plugins
i have deactivated my theme
and i’ve tried to overwrite
all the files on the server
but nothing helps