anybody has any ideas?
I managed to fix it by hardcoding the php script (/var/www/html/admin/modules/page.daynight.php as below.
<?php
$extdisplay=true; // here is the line.
echo form_action_bar($extdisplay);
?>
Secondly, when deleting any call flow items, there is no "Apply Config" on the top so I add needreload() before ending of daynight_del function. Then the "Apply Config" button will show on the screen.