Magento报错:Call to a member function extend() on a non-object in app\code\core\Mage\Core\Model\Mysql4\Config.php on line 115

遇到报错:Fatal error: Call to a member function extend() on a non-object in \app\code\core\Mage\Core\Model\Mysql4\Config.php on line 115

错误原因及解决办法参见:

Magento错误 - Notice: Undefined index:***app\code\core\Mage\Core\Model\Mysql4\Config.php on line 92的解决办法

里的

SET FOREIGN_KEY_CHECKS=0;
update `core_store` set store_id = 0 where code='admin';
update `core_store_group` set group_id = 0 where name='Default';
update `core_website` set website_id = 0 where code='admin';
update `customer_group` set customer_group_id = 0 where customer_group_code='NOT LOGGED IN';
SET FOREIGN_KEY_CHECKS=1;

执行一遍清缓存就OK。