title: Visual Studio 2017 - Could not load file or assembly 'System.Runtime, Version=4.1.0.0' or one of its dependencies
body: <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>