Plugin Error after updating to 4.6

On our website, when we updated wordpress, the admin page didnt work due to a plugin issue. When we tried to fix it on the ftp server side by deleting all plugins and reinstalling them, it just got worse and the whole website is down. There seems to be a problem with the plugin slimstat specifically in the php files.
Here is the error message:
Fatal error: Class ‘slim_browscap_db’ not found in /home/wmod/northvilledeca.com/wp-content/plugins/wp-slimstat/browscap/browser.php on line 22