title: .Net framework upgrade from 4 to 4.5.2
body: <p>We currently have a Winforms application targeting .NET Framework 4.</p>
  <p>When trying to upgrade to 4.5.2 we get an error:</p>
  <blockquote>
  <p>The type 'Object' is defined in an assembly that is not referenced. You must add a reference to assembly 'netstandard, Version=2.0.0.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51'</p>
  </blockquote>
  <p>How do we go about the upgrade?</p>
  <p>Any help would really be appreciated.</p>