1、开口加上session_start() http://metah.ch/blog/2014/05/facebook-sdk-4-0-0-for-php-a-working-sample-to-get-started/

2、http://stackoverflow.com/questions/23501811/new-facebook-sdk-4-throw-exception-about-php-session-active-in-laravel 重写了两个方法:

protected function storeState($state)    {        Session::put(‘facebook.state‘, $state);    }    protected function loadState()    {        return $this->state =  Session::get(‘facebook.state‘);    }

3、一个youtube的视频 https://www.youtube.com/watch?v=tRWlWuOWe8I

Session not active, could not store state 的解决方法