删除应用程序请求时出现未知错误

Question

这是我得到的错误

error OAuthException: (#2) User can't delete this request: Unknown error

这是我使用Requests 2.0的代码

try {
 $delete_success = $facebook->api("/$requestid"."_$fbprofileid&access_token=$config[appId]|$config[secret]",'DELETE');
 if ($delete_success) {
    echo "Successfully deleted " . $requestid;
} else {
   echo "Error: Your invitation wasn't deleted.".$requestid;}
}          
catch (FacebookApiException $e) { echo "error $e"; }