Update Error

A few moments ago I let my wordpress update automatically.
But now when I view my site this error comes up

Warning: require(/var/www/vhosts/divachoice.co.uk/httpdocs/wp-includes/class-wp-theme.php) [function.require]: failed to open stream: No such file or directory in /var/www/vhosts/divachoice.co.uk/httpdocs/wp-settings.php on line 115

Fatal error: require() [function.require]: Failed opening required '/var/www/vhosts/divachoice.co.uk/httpdocs/wp-includes/class-wp-theme.php' (include_path='.:') in /var/www/vhosts/divachoice.co.uk/httpdocs/wp-settings.php on line 115

Any clue on how to fix this?

Thanks in advance