title: At least one object must implement IComparable
body: <pre><code>var listair = empcon.OrderBy(x =&gt; x.CustomerConnection.OrderBy(y =&gt; y.Id)).ToList();
  </code></pre>
  
  <p>When I am using this statement then I am getting exception "At least one object must implement IComparable"</p>
  
  <p>How can I solve this problem?</p>