I found the problem. Google chrome was blocking mixed content.
In config.php the line:
// HTTPS
define('HTTPS_SERVER', 'http://yourdomain.com/');
needs to be changed to:
// HTTPS
define('HTTPS_SERVER', 'https://yourdomain.com/');
Is this an install script bug and if so do you want me to create an issue on GitHub? @eris @Raphael