Referencing a .NET Standard library from a Windows Class Library

There are two projects in my solution currently: a and another class library that targets I'm using Visual Studio 2015 Update 3.

I've added a reference to the .NET Standard project from the other project and it appears in the list of references, but I can't see any of the classes or namespaces from the referenced library when I want to use them (even though the referenced library was successfully built and has no errors).

This is the project.json for the .NET Standard library project:

{
  "version": "1.0.0-*",

  "dependencies": {
    "NETStandard.Library": "1.6.0"
  },

  "frameworks": {
    "netstandard1.3": {
      "imports": "dnxcore50"
    }
  }
}

I thought that .NET 4.6.1 projects can use .NET Standard 1.3 libs, and I even tried to use lower versions (1.0), but the result is the same. What am I missing here?

If I run

it also works fine:

log  : Restoring packages for C:\Users\Zsolt\Documents\Visual Studio 2015\Projects\PWB\PWBSpreadsheet.Entities\project.json...
log  : Restoring packages for C:\Users\Zsolt\Documents\Visual Studio 2015\Projects\PWB\PWBSpreadsheet.Parser\project.json...
log  : Writing lock file to disk. Path: C:\Users\Zsolt\Documents\Visual Studio 2015\Projects\PWB\PWBSpreadsheet.Parser\project.lock.json
log  : C:\Users\Zsolt\Documents\Visual Studio 2015\Projects\PWB\PWBSpreadsheet.Parser\PWBSpreadsheet.Parser.xproj
log  : Restore completed in 408ms.
log  : Writing lock file to disk. Path: C:\Users\Zsolt\Documents\Visual Studio 2015\Projects\PWB\PWBSpreadsheet.Entities\project.lock.json
log  : C:\Users\Zsolt\Documents\Visual Studio 2015\Projects\PWB\PWBSpreadsheet.Entities\PWBSpreadsheet.Entities.xproj
log  : Restore completed in 417ms.