Why do I get a missing references error asking for System.Runtime and System.Object

Question

VS2013 , new WPF/VB.NET project, using Framework 4.5.2, and NuGet MVVMLight Libraries Only.

Imports GalaSoft.MvvmLight
Imports System.Collections.ObjectModel
Imports GalaSoft.MvvmLight.Command
Public Class LoginViewModel
    Inherits ViewModelBase  '<-------------THIS LINE
End Class

Will Not Complile: error a reference is required for System.Runtime and System.ObjectModel if added, then it works correctly.

These references are not shown in the available list when using the standard "add references" feature, but if I use the "error suggestions" on the above line of code it will add references in for me.

What am I doing wrong that I have to make these manual and seemingly unorthodox adjustments?

thanks Josh

Answer 1

看起来这是known issue，我下载了该KB文章中链接的第一个包（328MB），并在运行安装程序后解决了错误。

更新：原来这不起作用，我刚刚在项目中添加新类后再次收到错误。