Hi,

Sorry, it’s misspelling, and we will update for new version. I’ve solved for you. Please check again.
I’ve eddited ‘Mage_Adminhtml_Controller_action’ to ‘Mage_Adminhtml_Controller_Action’ on 2 files:
app\code\local\Sns\Megamenu\controllers\Adminhtml\MenugroupController.php
app\code\local\Sns\Megamenu\controllers\Adminhtml\MenuitemsController.php

Thanks you,