i have been using the plugin very well for about two months, now i have this issue in the line 693
// Error detection:
if (array_key_exists('errors', $response))
throw new FacebookUnreachableException(!empty($response->errors) ? array_pop(array_pop($response->errors)) : '');
$json_response = json_decode($response['body']);
if (is_object($json_response) and property_exists($json_response, 'error')) {
throw new FacebookUnexpectedErrorException((is_object($json_response->error) and property_exists($json_response->error, 'message')) ? $json_response->error->message : '');
}