Vacation plugin not compatible with Roundcube 0.95, due to changes in the way roundcube access database.
To fix this, replace:$db = new rcube_mdb2($dsn, '', FALSE);with:
if (!class_exists('rcube_db')) { $db = new rcube_mdb2($dsn, '', FALSE); } else { $db = rcube_db::factory($dsn, '', FALSE); }in /plugins/vacation/lib/drivers/sql.php lines 34 and 173 web