Javascript Facebook发送对话框：发生错误。请稍后再试

我正在尝试使用FB发送对话框API。除了一个特定的用户之外，它对大多数用户都适用

  FB.init({appId: fbappid, xfbml: true, cookie: true});
 FB.getLoginStatus(function(response) {
          if (response.status === 'connected') { 
     FB.ui({
      method: 'send',
  to: 'username',
  display: 'iframe',
      name: 'I just suggested a time and place',
      link: linkval,
  picture: 'http://'+domain+'/img/cupicon.png',
  access_token: response.authResponse.accessToken     // **This should work and tested** also!!!
      })

          };
    });

---

原因是我得到了以下错误：对象{error\u code:100，error\u msg:“Viewer+cannot+message+specified+recipients.”

这是一个基于给定用户设置的权限问题