Error trying to get accesstoken - php

Question

I need to create a system that when the cliente publish something in his website it will be published in his facebook, but to do this i need to get the access token because the account need to still logged to my system.
I made my app and tested it in my own facebook and when i try to login by my system it work, but when i try to login with the system in the client facebook, return this error:
An error has occurred. Try again later.
My code to generate the AccessToken is this:
require_once("php-sdk/src/facebook.php"); //Up-to-date SDK files from Git
$app_id = "APP_ID"; //ID do APP
$app_secret = "APP_SECRET"; //Secret do APP
$facebook = new Facebook(array(
'appId' => $app_id,
'secret' => $app_secret
));
$page_id = 'PAGE_ID';
$message = "Teste de integração";
$token_url = 'https://graph.facebook.com/oauth/access_token?'
. 'client_id=' . $app_id
. '&client_secret=' . $app_secret
. '&grant_type=client_credentials';
$token_response = file_get_contents_curl($token_url);
$params = null;
parse_str($token_response, $params);
$app_access_token = $params['access_token'];
// Get User ID
$user = $facebook->getUser();
if ($user) {
try {
$page_info = $facebook->api("/$page_id/?fields=access_token");
//print_r($page_info);
if( !empty($page_info['access_token']) ) {
//if(!empty($app_access_token)) {
$args = array(
'access_token' => $page_info['access_token'],
'message' => $message
);
// print_r($args);
// $post_id = $facebook->api("/$page_id/feed","post",$args);
} else {
$permissions = $facebook->api("/me/permissions");
if( !array_key_exists('publish_stream', $permissions['data'][0]) ||
!array_key_exists('manage_pages', $permissions['data'][0])) {
// We don't have one of the permissions
// Alert the admin or ask for the permission!
header( "Location: " . $facebook->getLoginUrl(array("scope" => "publish_stream, manage_pages")) );
}
}
} catch (FacebookApiException $e) {
error_log($e);
$user = null;
}
}
// Login or logout url will be needed depending on current user state.
if ($user) {
$logoutUrl = $facebook->getLogoutUrl();
} else {
$loginUrl = $facebook->getLoginUrl(array('scope'=>'manage_pages,publish_stream, offline_access'));
}
?>
<?php if (!$user): ?>
Login with Facebook
<?php endif ?>
I already try to reconfig the user and all the config from the user is the same from the another account that didnt return the error.