Facebook Login issue (PHP SDK)

Reason:

After enabling strict mode and force HTTPS redirect URI, login process is not working for weird reasons. Here are some steps required:

Error: cross domain issue

  1. composer update
  2. Change default version to v2.10
  3. Add this script after creating a helper: (Very important!!) 
    if (isset($_GET['state'])) {
    $helper->getPersistentDataHandler()->set('state', $_GET['state']);
}

Reference: