title: Cannot step into .NET framework source code
body: <p>I am using Visual Studio 2013 and have a .NET 4.5.2 project. I have setup my settings according to following page:</p>
  
  <p><a href="http://referencesource.microsoft.com/setup.html" rel="noreferrer">http://referencesource.microsoft.com/setup.html</a></p>
  
  <p>With this setup, I can see that all necessary symbols are downloaded and loaded but I cannot step into a code like the following:</p>
  
  <pre><code>var cookieContainer = new System.Net.CookieContainer();
  </code></pre>
  
  <p>I am getting a <strong>Source Not Available</strong> message.</p>
  
  <p>I can step into the following code just fine:</p>
  
  <pre><code>Console.WriteLine("test");
  </code></pre>
  
  <p>Do you have any idea why I can step into code from mscorlib.dll but cannot step into code from System.dll?</p>