PM> Update-Package –reinstall EntityFramework
Attempting to gather dependencies information for multiple packages with respect to project 'SmartCentre', targeting '.NETFramework,Version=v4.5.2'
Update-Package : An item with the same key has already been added.
At line:1 char:15
+ Update-Package <<<<  –reinstall EntityFramework
    + CategoryInfo          : NotSpecified: (:) [Update-Package], Exception
    + FullyQualifiedErrorId : NuGetCmdletUnhandledException,NuGet.PackageManagement.PowerShellCmdlets.UpdatePackageCommand

<?xml version="1.0" encoding="utf-8"?>
<packages>
  <!-- ... -->
  <package id="Microsoft.AspNet.Web.Optimization" version="1.0.0" targetFramework="net40" />
  <package id="Microsoft.AspNet.Web.Optimization" version="1.1.2" targetFramework="net40" />
  <!-- ... -->
  <package id="Newtonsoft.Json" version="4.5.11" targetFramework="net40" />
  <package id="Newtonsoft.Json" version="5.0.8" targetFramework="net40" />
  <!-- ... -->
</packages>

<?xml version="1.0" encoding="utf-8"?>
<packages>
  <!-- ... -->
  <package id="Microsoft.AspNet.Web.Optimization" version="1.1.2" targetFramework="net40" />
  <!-- ... -->
  <package id="Newtonsoft.Json" version="5.0.8" targetFramework="net40" />
  <!-- ... -->
</packages>

<package id="Newtonsoft.Json" version="8.0.3" targetFramework="net40" />

<package id="Newtonsoft.Json" version="9.0.1" targetFramework="net40" />