title: Application pools won't run
body: <p>I have two servers sitting behind a loadbalancer in my service tier.  Both of them should be identical - IIS setup the same, AppFabric (to keep two services warmed up), app pools running under either a service account or the app pool identity.  On one server, everything works.  On the other server, three of my app pools (the two that AppFabric is warming up, under the service accounts, and one that's just a standard app pool with no changes made from default settings) stop running almost as soon as I start them up (sometimes on the first request).</p>
  
  <p>I get five of the following error in the Application log each time I try to start one of the app pools:</p>
  
  <blockquote>
    <p>There was an error during processing of the managed application service auto-start for configuration path: 'MACHINE/WEBROOT/APPHOST/Site/App'. The error message returned is: ''.  The worker process will be marked unhealthy and be shutdown.  The data field contains the error code.</p>
  </blockquote>
  
  <p>The error code referenced is <code>80070005</code>.</p>
  
  <p>This is actually for the same Site/App regardless of the app pool being started (though it may change after recreating the app pools).</p>
  
  <p>In the System log, I get the following warning five times before it errors (<code>Application pool 'AppPool' is being automatically disabled due to a series of failures in the process(es) serving that application pool.</code>):</p>
  
  <blockquote>
    <p>A process serving application pool 'AppPool' reported a failure during application preloading or service loading. The process id was '2396'.  Please ensure that all application preload or service settings in the application pool are configured properly.  The data field contains the error number.</p>
  </blockquote>
  
  <p>The error code referenced is <code>80004005</code>.</p>
  
  <p>The AppPool here is the one being started.</p>
  
  <p>I've tried recreating; I've tried uninstalling AppFabric (but we need it, so reinstalled and still no go).  I'm out of ideas.  Any suggestions?</p>
  
  <p><strong>EDIT</strong>:  I tried copying the applicationHost.config over from the working server, but that didn't work either..</p>
  
  <p><strong>EDIT2</strong>:  One of the app pools works when running under a real user account but doesn't when running under the ApplicationPoolIdentity....</p>
  
  <p>(Also, we had an issue where the site was running under 2.0 and the apps were running under 4.0.  That may have resolved the ones that are running as the service accounts.)</p>