WordPress 3.7.1

Hello I have a —Fatal error: Call to a member function reset_postdata() on a non-object in /home/europ307/public_html/venues/wp-includes/query.php on line 118….
I have tried everything… but cannot fix..
I have been reading all to do with this problem on wordpress, but no joy..
My problem seems to be my widgets on wordpress are only showing half, some work and some don’t…I have turned of all plugins but no joy…I have also re installed wordpress update 3.7.1 many times with plugins both on and off…I have spent a lot of time getting nowhere on wordpress….
Please help……