[Dragonsys]

try this as well:

Open: /includes/facebook/base_facebook.php
Find:

PHP Code:

  public static $CURL_OPTS = array(
    CURLOPT_CONNECTTIMEOUT => 10,
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_TIMEOUT        => 60,
    CURLOPT_USERAGENT      => 'facebook-php-3.2',
  ); 


Replace With:

PHP Code:

  public static $CURL_OPTS = array(
    CURLOPT_CONNECTTIMEOUT => 10,
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_TIMEOUT        => 60,
    CURLOPT_USERAGENT      => 'facebook-php-3.2',
    CURLOPT_SSL_VERIFYPEER => false,
    CURLOPT_SSL_VERIFYHOST => false,
  ); 


Untested by me, use with caution.
Source - http://stackoverflow.com/questions/1...-redirect-loop

--------------- Added [DATE]1450729157[/DATE] at [TIME]1450729157[/TIME] ---------------

Originally Posted by Dave

Are you running the latest version of vBulletin 4?

4.2.3 beta 3 (or higher) is required for FB connect to function properly

--------------- Added [DATE]1450731203[/DATE] at [TIME]1450731203[/TIME] ---------------

Let us know if this works, or if what Lynne mentioned here works, after you get a chance to try them.