reference of powerbi.js in MVC project

Hi

added the powerbi.js reference in _layouts'cshtml.

<script src="@Url.Content("~/js/powerbi.js")"></script>

When I run the webapp in IISexperess mode , this js was referenced correctly
but when I run webapp in Local IIS ( Project Properties -- > Web -- > Local IIS)
powerbi.js is not referenced at all.. (alert added to this js file was not called )

similarly i have added other js files , it works fine except , powerbi.js

Please help