请找到 这个文件夹：

app\code\core\Mage\Core\Model\Session\Abstract

然后修改Varien.php这个文件：

找到代码（大约88行）：

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

将后面的三个注释一下就可以了：

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

然后重新登陆一下。就可以进去后台了。

如果不行还要注释一句：

// if (isset($cookieParams['domain'])) {
// $cookieParams['domain'] = $cookie->getDomain();
// }

如果不行就注释以下代码：

// 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();
}
*/