title: Cannot install Entity Framework 6.1.3 in Visual Studio 2015 ''Object reference not set to an instance of an object"
body: <p>When I'm trying to install EF 6.1.3 on class library project in Visual Studio 2015 RTM  I face this error: <code>Object reference not set to an instance of an object</code>. </p>
  
  <blockquote>
    <p>Attempting to resolve dependencies for package 'entityframework.6.1.3'
     with DependencyBehavior 'Lowest' </p>
    
    <p>Resolving actions to install package
    'entityframework.6.1.3' </p>
    
    <p>Resolved actions to install package 'entityframework.6.1.3' </p>
    
    <p>Install failed. Rolling back... Package
    'EntityFramework 6.1.3' does not exist in project 'xxx.DataAccess'</p>
    
    <p>Package 'EntityFramework 6.1.3' does not exist in folder
     'xxx\packages' install-package :</p>
    
    <p>Object reference not set to an instance of an object. At line:1 char:1
    + install-package entityframework
    + ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
        + CategoryInfo          : NotSpecified: (:) [Install-Package], Exception
        + FullyQualifiedErrorId : NuGetCmdletUnhandledException,NuGet.PackageManagement.PowerShellCmdlets.InstallPackageCommand</p>
  </blockquote>
  
  <p>My project target framework is 4.5.2 and windows ver is 10.</p>