title: Facebook Messenger API : An active access token must be used to query information about the current user
body: <p>I'm following the development guide here: <a href="https://developers.facebook.com/docs/messenger-platform/quickstart" rel="noreferrer">https://developers.facebook.com/docs/messenger-platform/quickstart</a></p>
  
  <p>I've setup my server and the webhooks. When I try to make a POST request to the facebook graph api, I get the following response:</p>
  
  <pre><code>{"response":{"statusCode":400,"content":"{\"error\":{\"message\":\"An active access token must be used to query information about the current user.\",\"type\":\"OAuthException\",\"code\":2500,\"fbtrace_id\":\"GHWSIH8OBGm\"}}","headers":{"www-authenticate":"OAuth \"Facebook Platform\" \"invalid_request\" \"An active access token must be used to query information about the current user.\"","access-control-allow-origin":"*","pragma":"no-cache","cache-control":"no-store","facebook-api-version":"v2.6","expires":"Sat, 01 Jan 2000 00:00:00 GMT","content-type":"text/javascript; charset=UTF-8","x-fb-trace-id":"GHWSIH8OBGm","x-fb-rev":"2296043","vary":"Accept-Encoding","x-fb-debug":"4KebPKo5T+Al/88Z7DWtZ8ROawIB3cZFLp65OVi/soTB6hOHstvXox5czalYj45FdI+2r+MQwNh9PHur5uGSbQ==","date":"Wed, 20 Apr 2016 23:45:26 GMT","transfer-encoding":"chunked","connection":"keep-alive"},"data":{"error":{"message":"An active access token must be used to query information about the current user.","type":"OAuthException","code":2500,"fbtrace_id":"GHWSIH8OBGm"}}}}
  </code></pre>
  
  <p>I'm using the Page Access Token provided by the apps page. I used the fb token validator to validate that the token has not expired.</p>
  
  <p>I appreciate any help with this.</p>