If you want to edit Mega Menu or Footer with WP Bakery plugin, you have to do follow this steps belows:
Go to WPBakery Page Builder > Role Manage.
- Post Types: Choose “Custom” types.
- Click on “Megamenu, Footer, Page… or any other option which you want to use with Visual Editor.
- After all, click “Save Changes” to save your settings.
After you enable WPBakery Page Builder for Mega Menu, Footer, Product… the Menu Builder and Footer Builder will look like this images below: