Unable to load tooltip content

Hi everyone,

Just a minor issue: By enabling "User K2 - App", Tooltip for notifications no longer works on my website.

PHP Fatal error: Class 'SocialUserAppK2HookNotificationComments' not found in /var/www/familyclub.fr/administrator/components/com_easysocial/includes/apps/dependencies.php on line 272, referer: http://www.familyclub.fr/Communaute/Tableaudebord/all

Thanks !