title: How to update/upgrade the Facebook API version?
body: <p>How do I upgrade/update my Graph API ver from 2.1 to 2.5?</p>
  
  <ul>
  <li>The latest Graph API version of Facebook is v2.5.</li>
  <li>App A uses Graph API v2.1. This app has some login error which does not allow my app to login with the FB credentials.</li>
  <li>Another app uses v2.4, and this allows the login without issue.</li>
  </ul>
  
  <p>So, I was thinking of updating/upgrading my App A's graphAPI to v2.4 or 2.5. However, their official doc does not specifically state how to upgrade it but rather just the call method. </p>
  
  <p><strong>Software</strong></p>
  
  <ul>
  <li>Unity ver: 4.6.9 f1 </li>
  <li>Facebook Unity SDK 6.2.2 </li>
  <li>iOS SDK 3.2.0</li>
  </ul>