ReferenceError: head is not defined

[syesudas]

I tried both grunt dev & grunt prod.
Both the ways when I open the index.html page in browser it is throwing below error in the browser console.

"NetworkError: 404 Not Found - http://localhost/Quizzler/vendor/headjs-notify/src/load.js"
load.js

ReferenceError: head is not defined
at
}( window, head ));