Manual upgrade problem

I just did a manual upgrade for teamargus.com and now I can’t login. Getting this error code:

Warning: require(/home/teamargu/public_html/wp-includes/class-wp-theme.php) [function.require]: failed to open stream: No such file or directory in /home/teamargu/public_html/wp-settings.php on line 111

Fatal error: require() [function.require]: Failed opening required ‘/home/teamargu/public_html/wp-includes/class-wp-theme.php’ (include_path=’.:/usr/lib/php:/usr/local/lib/php’) in /home/teamargu/public_html/wp-settings.php on line 111

Please help!!