title: ObjectContext instance has been disposed using LINQ and cannot get a JSON result
body: <p>I would to make an ASP.NET MVC API with data from my database. To do this I use LINQ. I create my context and get all tariffs where <code>delete</code> is false.</p>
  
  <pre class="lang-csharp prettyprint-override"><code>[HttpGet]
  public JsonResult Index()
  {
      List&lt;Tariff&gt; temp = new List&lt;Tariff&gt;();
      using (Context context = new Context())
      {
          temp = context.Tariff.Where(t =&gt; !t.Delete).ToList&lt;Tariff&gt;();
      }
      return Json(temp, JsonRequestBehavior.AllowGet);
  }
  </code></pre>
  
  <p>When I debug, temp contains a List of <code>System.Data.Entity.DynamicProxies.Tariff_...</code> instead of <code>MyNamespace.Models.Tariff</code>. When I continue it gives me this exception:</p>
  
  <blockquote>
    <p>The <code>ObjectContext</code> instance has been disposed and can no longer be used for operations that require a connection.</p>
  </blockquote>
  
  <p>What I'm doing wrong?</p>