title: using Newtonsoft.Json in c# not working even after downloading package
body: <p>I downloaded Newtonsoft.Json.11.0.2 package by package manager console,
  and it certainly showed that the package is installed in project.
  However, when I try to use the package</p>
  
  <pre><code>using Newtonsoft.Json
  </code></pre>
  
  <p>visual studio keeps warning me the name is not found and draws red underline.
  What should I do? uninstalling and reinstalling the package didn't work.</p>