Visual Studio 2017 - Could not load file or assembly 'System.Runtime, Version=4.1.0.0' or one of its dependencies : <p>I am using Visual Studio 2017 and am trying to create a .Net Standard 1.5 library and use it in a .Net 4.6.2 nUnit test project. </p>

<p>I am getting the following error...</p>

<blockquote>
  <p>Could not load file or assembly 'System.Runtime, Version=4.1.0.0,
  Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' or one of its
  dependencies. The system cannot find the file specified.</p>
</blockquote>

<p>I have tried the following:</p>

<ol>
<li><strong>Reference Std library as project reference.</strong> Error: gives me the previous error.</li>
<li><strong>Create a NuGet pkg for my Std library and reference that.</strong> Error: The type is System.String, expecting System.String. This is because System.Runtime ended up getting referenced by the project and it has definitions for all the standard types.</li>
<li><strong>Reference NuGet pkg NetStandard.Library.</strong> Error: give me the same error as # ("The type is System.String, expecting System.String"). NOTE: Before I did this, I cleared ALL NuGet packages from the project and then added just the nUnit and NetStandard.Library packages (which installed 45 other packages).</li>
</ol>

<p>Is this a bug? Is there a work-around? Any help is appreciated.</p>
