title: Why is Visual Studio Application Timelines not working?
body: <p>I'm trying to analyse performance of a WPF application using the Visual Studio 2015 <em>Application Timeline</em> tool. However, when I attempt to start the profiler, I receive the following error message:</p>
  
  <blockquote>
    <p>Diagnostics session failed to start.</p>
    
    <p>Failed to start trace session (0x00000005).</p>
  </blockquote>
  
  <p>I've tried:</p>
  
  <ul>
  <li>running as a privileged user. </li>
  <li>a smaller toy WPF project. </li>
  <li>checking event log for clues.</li>
  <li>googling :)</li>
  </ul>
  
  <p>No idea where to go next. Has anyone seen this issue before?</p>