title: A debugger is attached but not configured to debug this unhandled exception
body: <p>Yes, I know, I know, quite a few similar questions but the answers there just don't cut it for me. My setup might be a bit more complicated, maybe. The solution has two projects (both using .NET 4.5.2):</p>
  
  <ul>
  <li>a managed C# 64-bit (or possibly 32-bit) application,</li>
  <li>a C++/CLI Windows service, strictly 32-bit due to the SDKs used.</li>
  </ul>
  
  <p>The service has an unhandled access violation crash when run, not in my code but somewhere in the depths of the SDK calling back to my code. The Event Viewer tells me it's in <code>ntdll.dll</code> but nothing more.</p>
  
  <p>There are various ways to debug but the most convenient I found was to start the service as a standalone console application, with a <code>System::Diagnostics::Debugger::Launch()</code> call in its <code>Main()</code>. This allows me to attach it to the VS debugger. And it <em>is</em> running all right.</p>
  
  <p>I start the main application now and go to the part where the crash occurs. No matter whether I started it under a second VS debugger or running directly from the UI (Windows offers to choose a debugger in the second case), the next dialog will be the usual error message (see title). However:</p>
  
  <ul>
  <li>the projects are set to debug mixed code (service), native included (main app),</li>
  <li>the main app has <em>Allow unsafe code</em> set (for unrelated reasons, but some answers suggest that this helps mixed code debugging, too),</li>
  <li>the debugger is set to handle <em>all</em> Win32 and C++ exceptions.</li>
  </ul>
  
  <p>So the usual problems leading to this error are accounted for. What else might cause that I'm unable to debug this service?</p>