Fatal error: Uncaught Error: Class "rcube_plugin" not found in /usr/local/www/roundcube/plugins/roundcube-plugin-kolab-2fa/kolab_2fa.php:24 Stack trace: #0 {main} thrown in /usr/local/www/roundcube/plugins/roundcube-plugin-kolab-2fa/kolab_2fa.php on line 24