Can't login into admin panel of Magento

[BhavikaJadav]

I am unable to login in magento admin panel. Magento ver. 1.9.2.4. I am using aws - cdn server with Load Balance. Reason is in every minute its calling this:

Error : {ajaxExpired: 1,…}
ajaxExpired
:
1
ajaxRedirect
: "https://www.gleitsichtbrille.de/index.php/ag_supervista/index/login/key/dc32322811d123b75356a1521949..."

I have followed below steps to solve this error:
(1) Clear browser cache, history,etc
(2) Delete cache folder from var.
(3) checked with below code to comment it in app\code\core\Mage\Core\Model\Session\Abstract\Varien.php and remove cache:

// session cookie params
    /*$cookieParams = array(
        'lifetime' => $cookie->getLifetime(),
        'path'     => $cookie->getPath(),
        'domain'   => $cookie->getConfigDomain(),
        'secure'   => $cookie->isSecure(),
        'httponly' => $cookie->getHttponly()
    );*/

(4) Set Permission 777 to cache and session folder.
(5) set web configuration "Use HTTP Only" to "No".

[BhavikaJadav]

On every click admin panel is redirecting to HTTP ERROR 500. Once I refresh the page it is working. Only click event is not working