java - Facebook Graph API: Attend to event always returns responseCode: 200, false -

i'm trying attend facebook user event,

request.executepostrequestasync(...) 

but server returns following:

{response:  responsecode: 200, graphobject: graphobject{graphobjectclass=graphobject, state={"facebook_non_json_result":false}}, error: null, isfromcache:false} 

the authentication works, can user infos, etc... tried laso link graph api explorer , worked there, should wrong code. checked permissions, allright. i'd pleased if me, here code:

list<string> permissions = new arraylist<string>(); permissions.add("rsvp_event");  private void attendtoevent(final string eventid){     session.openactivesession(mainactivity.this, true, new session.statuscallback() {          @override         public void call(session session, sessionstate state, exception exception) {              session actsession = session.getactivesession();             if (!hasrsvpeventpermission() && actsession.isopened()) {                 actsession.requestnewpublishpermissions(new session.newpermissionsrequest(mainactivity.this, permissions));             }              string accesstoken = actsession.getaccesstoken();             string path = new string("https://graph.facebook.com/"+eventid+"/attending");             if(session != null && session.isopened()){                 jsonobject jo = new jsonobject();                 final graphobject go = graphobject.factory.create(jo);                 request.executepostrequestasync(session, path, go, new request.callback() {                 //request.executegraphpathrequestasync(session, path, new request.callback() {                      @override                     public void oncompleted(response response) {                         system.out.println(response.tostring());                         showattendresult(response.getgraphobject(), response.geterror());                     }                 });             }         }     }); }  private boolean hasrsvpeventpermission() {     session session = session.getactivesession();     return session != null && session.getpermissions().contains("rsvp_event"); }  

i found out! problem was, instead of path:

string path = new string("https://graph.facebook.com/"+eventid+"/attending"); 

the graph api expects this:

string path = new string(eventid+"/attending"); 

so without "http://graph.facebook.com/" !