Fatal error: Uncaught Error: Class "rcube_plugin" not found in /usr/local/www/roundcube/plugins/twofactor_gauthenticator/twofactor_gauthenticator.php:18 Stack trace: #0 {main} thrown in /usr/local/www/roundcube/plugins/twofactor_gauthenticator/twofactor_gauthenticator.php on line 18