Facebook API错误致命错误:(未捕获OAuthException:验证应用程序时出错）

我是Facebook API的初学者。我刚刚创建了一个应用程序，我想显示朋友的姓名和数量：

这是我的代码：

<?php
require_once 'facebook-php-sdk/src/facebook.php';
$appapikey = '133XXXX60164049';
$appsecret = '  ce6a47dfd838WWWWWW34f387b28633660';
$facebook = new Facebook($appapikey, $appsecret);
$user_id = $facebook->getUser();
$friends = $facebook->api('/me/friends');
echo "<p>Hello <fb:name uid='"$user_id'" useyou='"false'" linked='"false'" firstnameonly='"true'"></fb:name>, you have ".count($friends)." friends";
foreach($friends as $friend){
     $infos.=$friend.",";
}
$infos = substr($infos,0,strlen($infos)-1);
$gender=$facebook->api_client->users_getInfo($infos,'sex');
$gender_array = array(); 
foreach($gender as $gendervalue){
     $gender_array[$gendervalue[sex]]++;
}
$male = round($gender_array[male]*100/($gender_array[male]+$gender_array[female]),2);
$female = 100-$male;
echo "<ul><li>Males: $male%</li><li>Females: $female%</li></ul>";
?>

我有这个

致命错误：未捕获OAuthException：验证应用程序时出错。由于系统错误，无法获取应用程序信息。在1238 行的D:''softs''UwAmp''www''facebook-php-sdk''src''base_facebook.php中抛出

我试着只显示这样的用户名：

<?php
require_once 'facebook-php-sdk/src/facebook.php';
$appapikey = '453976ergerger647366';
$appsecret = 'fexxxxxxxxeb39bbce717b8062';
$facebook = new Facebook($appapikey, $appsecret);
$user_id = $facebook->getUser();

echo "<p>Hello <fb:name uid='"$user_id'" useyou='"false'" linked='"false'" firstnameonly='"true'"></fb:name>";
 ?>

但它不起作用。只显示"Hello"：s