title: "are you missing a using directive or assembly reference?" Am I or am I not?
body: <p>Cleaned and rebuilt everything many times, restarted VS and computer but no progress. Patching some bugs in the QueryCommander open source project, I came across an issue where Debug builds, but Release does not. I get this error <strong>in Release mode only</strong>:</p>
  
  <pre><code>CS0246  The type or namespace name 'AxSHDocVw' could not be found (are you missing a using directive or an assembly reference?)
  QueryCommander.Help C:\Workspace\QueryCommander_4_0_0_0\QueryCommander.Help\WinGui\FrmHelpBrowser.cs
  </code></pre>
  
  <p>The reference does actually exists:</p>
  
  <p><a href="https://i.stack.imgur.com/ZP3Xo.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/ZP3Xo.jpg" alt="enter image description here"></a></p>
  
  <p>And it does contain the missing namespace:</p>
  
  <p><a href="https://i.stack.imgur.com/6POqt.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/6POqt.jpg" alt="enter image description here"></a></p>
  
  <p>The unit <code>FrmHelpBrowser.cs</code> does not have a <code>using</code> directive indeed, but I am not sure why that works in <code>Debug</code> mode and what should be used here:</p>
  
  <pre><code>using System;
  using System.Drawing;
  using System.Collections;
  using System.ComponentModel;
  using System.Windows.Forms;
  using QueryCommander.Help.WinGui.Base;
  
  namespace QueryCommander.Help.WinGui
  {
      /// &lt;summary&gt;
      /// Summary description for FrmHelpBrowser.
      /// &lt;/summary&gt;
      public class FrmHelpBrowser : FrmBaseContent
      {
          public AxSHDocVw.AxWebBrowser axWebBrowser1; // Error on this line
  //----------------^ here
  </code></pre>
  
  <p>What is missing in the release mode?</p>