title: Facebook SDK Android AppEventsLogger NullPointerException on flush
body: <p>I integrated the current FacebookSDK for Android v3.5 for tracking purposes.
  You can track app installs by calling
      com.facebook.AppEventsLogger.activateApp(context, YOUR_APP_ID);</p>
  
  <p>So far no problems, i can see these events are shown on the facebook dashboard.
  When it comes to track events or purchase events, facebook recomments doing the following:</p>
  
  <pre><code>m_fbAppEventsLogger = com.facebook.AppEventsLogger.newLogger(applicationcontext);
  m_fbAppEventsLogger.logPurchase(BigDecimal.valueOf(4.99), Currency.getInstance("USD"));
  </code></pre>
  
  <p>It seems that the purchase events get flushed immediately, which results in </p>
  
  <pre><code>09-22 15:10:04.680: D/com.facebook.AppEventsLogger(31691): Caught unexpected exception while flushing: java.lang.NullPointerException
  </code></pre>
  
  <p>If i try to send a custom event, the same error occurs if the facebook SDK decides to flush the events in its queue.</p>
  
  <p>I found nothing for this behavior, so any help would be greatly appreciated.</p>