Plugin – Menu Master Custom Menu – Not showing options in widget area

I’ve installed the plugin and set up the new menus using dedicated pages with custom fields as per the setup instructions here –

https://www.ads-software.com/extend/plugins/menu-master-custom-widget/

However, when I drag the widget item into the sidebar area in the ‘widgets’ section of ‘apppearance’ , it says that ‘there are no options for this widget’.

What am I doing wrong? any help greatly appreciated.