As you suggested on another thread, I'm installing this plugin. I'm confused by this instruction:
4. If you are installing this plugin on a Zen Cart version prior to v1.5.2, copy the plugin's file /before_zc152/includes/classes/class.core.php to the (currently empty) plugin directory /includes/classes. This is the version of the file distributed with the Zen Cart v1.5.2-RC2 release.

What is the (currently empty) supposed to mean? I have a lot of stuff in the /includes/classes directory, so it's not empty. The file in /before_zc152/includes/classes isn't called class.core.php, it's called class.base.php, which I already have in includes/classes. I've installed quite a few plugins over the years and I haven't had this issue before. Any help would be appreciated. Thanks! :)