I tried to upgrade to 3.4.1 and I now cannot access my dashboard or anything. I can't access the site at all. It displays this message 'Fatal error: require() [function.require]: Failed opening required '/home/a6772839/public_html/wp-includes/class-wp-theme.php' (include_path='.:/usr/lib/php:/usr/local/lib/php') in /home/a6772839/public_html/wp-settings.php on line 115'. My site is 21couture.co.uk.
Please, please somebody help me fix this! I very stupidly haven't backed up the site as I have only been running it for a week.