I'm getting a 500 error when trying to visit my page. Was able to track it down to this error in the logs, but can't seem to get it fixed. Updated the craft/app folder with the latest Craft version, but still no luck.
From my phperrors.log
[14-Mar-2017 17:56:34 UTC] PHP Fatal error: Uncaught Error: Class 'Craft\DbConnection' not found in /var/www/site/craft/app/etc/behaviors/AppBehavior.php:849