title: why I always get "Must have a valid access_token to access this endpoint"
body: <p>I am new to facebook. Sorry if I missed some simple part. I can successfully get access_token by from</p>
  
  <p><a href="https://graph.facebook.com/oauth/access_token?grant_type=client_credentials&amp;client_id=XXXXXXXX&amp;client_secret=XXXXXXXXX" rel="nofollow">https://graph.facebook.com/oauth/access_token?grant_type=client_credentials&amp;client_id=XXXXXXXX&amp;client_secret=XXXXXXXXX</a></p>
  
  <p>However, when I used it to do FQL query:</p>
  
  <pre><code>graph = GraphAPI(access_token=access_token, timeout=1000)
  query1 = "SELECT id, username, name  FROM profile WHERE contains('Client Name') AND type='user'"
  results = graph.fql(query1)
  </code></pre>
  
  <p>I got following error messages</p>
  
  <p>facebook.GraphAPIError: Must have a valid access_token to access this endpoint</p>
  
  <p>I am using python facebook-sdk for development. Any help will be highly appreciated!!</p>
  
  <p>Thanks!</p>