[SOLVED] Joomla 3.0 DS does not work(Use of undefined constant DS)

Joomla 3.0 DS does not work. It has been removed. I get

Notice: Use of undefined constant DS - assumed 'DS' in

How can I fix this?

Add the below line

if(!defined('DS')) define('DS', DIRECTORY_SEPARATOR);

From the docs.

The DS constant has been removed. If you really need it you can use DIRECTORY_SEPARATOR instead.

Also there is a plugin to fix this issue.

You can find the full list here.