Facebook graph api. App notifications: A client gets notification, but server gets error in the response: Unsupported post request

I'm developing server side by Java of an online game for facebook. I need to send app notifications using "facebook graph api". When I try to send a notification, facebook returns the next response:

{
   "error": {
      "message": "Unsupported post request. Please read the Graph API documentation at http://ift.tt/1cZ9288",
      "type": "GraphMethodException",
      "code": 100
   }
}

My request looks like this:

http://ift.tt/1HUQqCW

Most strange thing is I get notifications in my facebook account but my server side gets error after sending one and I can't understand if a user has gotten a notification. I wander if someone had problem like this. I will be appreciate your help! Thank you!