This is not coming from Joomla core, but from a 3rd party (likely custom developed) component that exist in your site.
First see if you really need/use this component, or you can simply uninstall it. If you need it, then look for any information you can gather for this component - find the developer and his site/email and ask if there is an update for Joomla 3. Such information you may be able to find in the component's files, e.g the
newtoy.xml file in the component's directory of the administrator site.
If there is no such info or no upgrade, then you will have to upgrade it.
Regarding this specific error about the
DS constant, you need to replace all "
DS" occurrences with the forward slash "
/" in the extension.
DS constant is no longer used in Joomla.
As a quick solution, you can define the
DS constant at your own:
A. Create a
defines.php at the root directory of your Joomla site.
defined('_JEXEC') or die;
// Custom definitions
Joomla will load this
defines.php file and the
DS constant will be defined across the site application.
B. At the top of the main index.php with (it will be overwritten at next Joomla update):
defined('DS') or define('DS', '/');
C. At the top of your script:
defined('DS') or define('DS', 'DIRECTORY_SEPARATOR');
This will solve temporary this error, but this change will be lost with the next Joomla update.
But probably there will be more changes you will need to make in order to upgrade the component and make it compatible with Joomla 3.
If you have no programming experience, then this task won't be very easy and it might be a good idea to hire someone.
You may find the following resources useful: