title: There was a conflict between "mscorlib, Version=4.0.0.0" and "mscorlib, Version=2.0.5.0"
body: <p>While playing with ASP.Net Core I tried to bring-in a custom code-library of my own and got these messages:</p>
  <blockquote>
  <p>No way to resolve conflict between &quot;mscorlib, Version=4.0.0.0,
  Culture=neutral, PublicKeyToken=b77a5c561934e089&quot; and &quot;mscorlib,
  Version=2.0.5.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e,
  Retargetable=Yes&quot;. Choosing &quot;mscorlib, Version=4.0.0.0,
  Culture=neutral, PublicKeyToken=b77a5c561934e089&quot; arbitrarily.</p>
  <p>No way to resolve conflict between &quot;System, Version=4.0.0.0,
  Culture=neutral, PublicKeyToken=b77a5c561934e089&quot; and &quot;System,
  Version=2.0.5.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e,
  Retargetable=Yes&quot;. Choosing &quot;System, Version=4.0.0.0, Culture=neutral,
  PublicKeyToken=b77a5c561934e089&quot; arbitrarily.</p>
  </blockquote>
  <p><strong>Q:</strong> Is it possible to make the 2 versions &quot;play well&quot; together?<br/>
  <strong>Q:</strong> Is it a good idea to even try?</p>
  <p><strong>NOTES:</strong><br/>
  running <code>update-package -reinstall</code> uninstalled all references to Entity Framework, Unity and so on...so this isn't the &quot;fix&quot;.</p>