I had a similar problem while trying to execute Install-Package Modernizr on Visual Studio 2015. I fixed my problem by following the below steps:
- Download the package from its online source.
- Go to Tools/NuGet Package Manager/Package Manager Settings.
- Select Package Sources from the window.
- Add a new package source by clicking on the + sign. Enter a name and source location by clicking on ... (triple dot) sign.
- Make sure that only the package source that you've just added is checked. Uncheck all the other package sources.
- Go to Package Manager Console and type
Install-Package Modernizr
.
- Visual Studio 2015 installs the package automatically and creates Scripts and packages folders in your root folder.
I hope the same solution works while installing other packages, too.