title: Visual studio mistakes valid code as invalid after debug edit
body: <p>I am using visual studio 2013 with unity 3.5 downloaded using nuget. I have Container class that looks like the following</p>
  
  <pre><code>  public class Container
    {
      static IUnityContainer _container; //&lt;- System IDisposable error on _container
      static ILogger _logger = GetLogger();
  
      //continuation here
    }
  </code></pre>
  
  <p>My problem is when I execute the application, debug runs fine, but if I edited a statement completely unrelated to the class above during debug process, when I resume debugging I get the following strange error with blue underline below <code>_container</code>!!</p>
  
  <p><img src="https://i.stack.imgur.com/LD6F3.png" alt="enter image description here"></p>
  
  <blockquote>
    <p>The type 'System.IDisposable' is defined in an assembly that is not
    referenced. You must add a reference to assembly 'System.Runtime,
    Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a'</p>
  </blockquote>
  
  <p>after this I will have to stop debug and restart again. without touching anything the error disappears and can debug back.</p>
  
  <p>I looked for System.Runtime assembly in Framework assemblies but I could not find it. the available assemblies are:</p>
  
  <blockquote>
    <p>System.Runtime.caching 
    System.Runtime.DurableInstancing
    System.Runtime.Remoting
    System.Runtime.Serialization
    System.Runtime.Serialization.Formatters.Soap</p>
  </blockquote>
  
  <p>any way how to at least track down this error?</p>