The social network Facebook has implemented a new version of the API 2.4, in which there have been changes regarding the authorization of users on websites. When creating new applications on this social network, they automatically receive this version of the API, as a result of which it was impossible for them to use authorization on your sites using this network, because the e-mail address was unavailable. To fix this problem, you need to open the file engine/classes/social.class.php find in it:

$params = array('access_token' => $token['access_token']);

replace with:

$params = array('access_token' => $token['access_token'], 'fields' => "id,name,email,first_name,last_name");

The distribution of version 10.5 on the official server has been updated.