title: why do I get "Invalid appsecret_proof provided in the API argument"
body: <p>Since the latest change on Facebook, regarding the appsecret_proof: <a href="https://developers.facebook.com/docs/reference/api/securing-graph-api/">https://developers.facebook.com/docs/reference/api/securing-graph-api/</a>, we are still unable to download performance reports even after enabling/disabling features from Advanced Settings in our app, or apply the code as described in their document.</p>
  
  <p>We are constantly getting this error:</p>
  
  <blockquote>
    <p>{"error":{"message":"Invalid appsecret_proof provided in the API argument","type":"GraphMethodException","code":100}}</p>
  </blockquote>
  
  <p>and I've open a confidential bug but no one returns to me with an answer.</p>
  
  <p>I really don't know what more could we try? </p>