Fatal error: Uncaught TypeError: join(): If argument #1 ($separator) is of type string, argument #2 ($array) must be of type array, null given in /home/www/pages/Wiki/plugin/backup.inc.php:101 Stack trace: #0 /home/www/pages/Wiki/plugin/backup.inc.php(101): join('', NULL) #1 /home/www/pages/Wiki/lib/plugin.php(108): plugin_backup_action() #2 /home/www/pages/Wiki/lib/pukiwiki.php(69): do_plugin_action('backup') #3 /home/www/pages/Wiki/index.php(23): require('/home/www/pages...') #4 {main} thrown in /home/www/pages/Wiki/plugin/backup.inc.php on line 101