Unable to find version '2.0.0' of package 'Microsoft.AspNetCore.Identity'

I'm running VS2017 v15.3 on Windows 7 x64.  I seem to have a problem installing nuget core 2.0 pkgs.  I've tried to install various asp.net core 2.0 pkgs in different applications and I keep getting the following err:


Install-Package : Unable to find version '2.0.0' of package 'Microsoft.AspNetCore.Identity'.
At line:1 char:1
+ Install-Package Microsoft.AspNetCore.Identity -Version 2.0.0
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : NotSpecified: (:) [Install-Package], Exception
    + FullyQualifiedErrorId : NuGetCmdletUnhandledException,NuGet.PackageManagement.PowerShellCmdlets.Inst
   allPackageCommand


You can substitute Microsoft.AspNetCcore.Identity w virtually any aspnet core pkg and get the same error.

If I browse and search for the pkg only v1.1.2 comes up.  The about box says I'm running VS2017 v15.3.3 and I recently ran a repair using the VS installation.

The project I'm currently working on is an AspNetCore 2.0 library, but I seem to get the same error regardless of the project.