Sometime, the apps that link to the Facebook is having the time out issue and your server end receive the error as below
Fatal error: Uncaught CurlException: 28: SSL connection timeout thrown in ..\..\base_facebook.php
Solution:
(1) edit the file base_facebook.php
(2) edit the link as below
CURLOPT_CONNECTTIMEOUT => 10
(3) to as below.
CURLOPT_CONNECTTIMEOUT => 30
This to extend the time out from 10s to 30s