title: VS2012 breaks previously functioning .NET ActiveX object in IE 8
body: <p>(Yes, I work in a large corporate environment, which is why I'm talking about all of this backwards technology.  No, I don't have the option currently to gut the thing and rewrite it in this decade's technology.)</p>
  
  <p>We have an application that needs to do some client-side work in .NET, but needs to be launched from a web application.  The way that the dev (working in 2004ish) chose to do this was to have the web site output an  tag that points at a .NET DLL on the server and launches a WinForms UserControl inside of that DLL.</p>
  
  <p>The HTML that gets rendered in the web page looks like this:</p>
  
  <pre><code>&lt;OBJECT id=launcher    
  classid=http://server.com/Path/To/The.dll#Full.Namespace.Path.To.TheUserControl 
  width=640 height=300 VIEWASTEXT&gt;
    &lt;PARAM NAME="SomeParam" VALUE="SomeParamValue"&gt;
  &lt;/OBJECT&gt;
  </code></pre>
  
  <p>This was working in production for many years.  But now, when our developers install VS2012, it stops working.  After a 2012 install, where previously they would see the user control rendered in a box inside of the IE page, they now see a big X (like a broken image).  No other feedback is given as to what might be the problem.  Note that this is true whether the dev runs the code locally, or runs it on the server where it is deployed for the users (and working fine on machines that don't have VS2012).</p>
  
  <p>I'm having trouble even diagnosing this problem.  Are there any known issues with a VS2012 install (or .NET 4.5 which is also installed) impacting the execution of ActiveX controls in Internet Explorer (we are using IE 8 if it matters)?  How should I go about finding out what is wrong?</p>