title: WCF DataService returns An error occurred while processing this request
body: <p>I have a strange promblem with DataServices when executing specific query:</p>
  
  <p><code>http://localhost:58362/DataService.svc/A?$expand=B/C</code> works as expected</p>
  
  <p><code>http://localhost:58362/DataService.svc/C?$expand=D</code> works as expected</p>
  
  <p>On Query:</p>
  
  <p><code>http://localhost:58362/DataService.svc/A?$expand=B/C/D</code>
  I get </p>
  
  <pre><code>{
      odata.error: {
          code: ""
          message: {
              lang: "en-EN"
              value: "An error occurred while processing this request."
          }
      }
  }
  </code></pre>
  
  <p>No exceptions in visual. Just this result without more messages.</p>
  
  <p>Can it be connected with amount of data?</p>