Why I am getting invalid_request from Graph api when invoked from my app? - facebook

Question

When I make the following request from browser, it works.
https://graph.facebook.com/app?access_token=<a valid token>
However, this same call fails with the following error when done from my code, for the exact same token which worked in the browser.
2 * Client out-bound request
2 > GET https://graph.facebook.com/app?access_token=<the fb token>
2 * Client in-bound response
2 < 400
2 < Content-Type: text/javascript; charset=UTF-8
2 < WWW-Authenticate: OAuth "Facebook Platform" "invalid_request" "Unsupported get request. Please read the Graph API documentation at https://developers.facebook.com/docs/graph-api"
2 < Access-Control-Allow-Origin: *
2 < X-FB-Rev: 1674690
2 < Pragma: no-cache
2 < Cache-Control: no-store
2 < Facebook-API-Version: v1.0
2 < Expires: Sat, 01 Jan 2000 00:00:00 GMT
2 < X-FB-Debug: <some string>
2 < Date: Mon, 06 Apr 2015 13:46:57 GMT
2 < Connection: keep-alive
2 < Content-Length: 183
2 <
{"error":{"message":"Unsupported get request. Please read the Graph API documentation at https:\/\/developers.facebook.com\/docs\/graph-api","type":"GraphMethodException","code":100}}
My client-side code which makes this call is:-
ClientResponse r = httpClient.resource("https://graph.facebook.com/app")
.queryParam("access_token", fbAccessToken).accept(MediaType.APPLICATION_JSON)
.get(ClientResponse.class);
FBAccessTokenResponse res = r.getEntity(FBAccessTokenResponse.class);
return res;
The other interesting fact is that the app code works if the fb token is for me (the app developer) or few FB test users. For other actual users it fails with this error, for my app only.