Some cookie issue, if you are running on a local host than you may experience this problem. So … locate app\code\core\Mage\Core\Model\Session\Abstract\Varien.php
open with ant editor, or notepad, and make comment like this:
// session cookie params
$cookieParams = array(
‘lifetime’ => $cookie->getLifetime(),
‘path’ => $cookie->getPath(),
// ‘domain’ => $cookie->getConfigDomain(),
//’secure’ => $cookie->isSecure(),
//’httponly’ => $cookie->getHttponly()
);
/*
if (!$cookieParams['httponly']) {
unset($cookieParams['httponly']);
if (!$cookieParams['secure']) {
unset($cookieParams['secure']);
if (!$cookieParams['domain']) {
unset($cookieParams['domain']);
}
}
}
if (isset($cookieParams['domain'])) {
$cookieParams['domain'] = $cookie->getDomain();
}
*/