title: Meaning/cause of RPC Exception 'No interfaces have been exported.'
body: <p>We have a fairly standard client/server application built using MS RPC. Both client and server are implemented in C++. The client establishes a session to the server, then makes repeated calls to it over a period of time before finally closing the session.</p>
  
  <p>Periodically, however, especially under heavy load conditions, we are seeing an RPC exception show up with code 1754: <code>RPC_S_NOTHING_TO_EXPORT</code>.</p>
  
  <p>It appears that this happens in the middle of a session. The user is logged on for a while, making successful calls, then one of the calls inexplicably returns this error. As far as we can tell, the server receives no indication that anything went wrong - and it definitely doesn't see the call the client made.</p>
  
  <p>The error code appears to have permanent implications, as well. Having the client retry the connection doesn't work, either. However, if the user has multiple user sessions active simultaneously between the same client and server, the other connections are unaffected.</p>
  
  <p>In essence, I have two questions:</p>
  
  <ol>
  <li><p>Does anyone know what <code>RPC_S_NOTHING_TO_EXPORT</code> means?  The MSDN documentation simply says: <code>"No interfaces have been exported."</code> ... Huh? The session was working fine for numerous instances of the same call up until this point...</p></li>
  <li><p>Does anyone have any ideas as to how to identify the real problem? <em>Note</em>: Capturing network traffic is something we would rather avoid, if possible, as the problem is sporadic enough that we would likely go through multiple gigabytes of traffic before running into an occurrence.</p></li>
  </ol>