Enable Joomla Legacy Mode to fix problems with old Joomla extensions
Joomla Legacy mode is needed to run Joomla 1.0 components, modules or plugins which have not been migrated to Joomla 1.5.
Enabling the Legacy mode is not very straightforward. This is done by enabling a system plugin. To enable the plugin, you need to go to Extensions > Plugin Manager, find the plugin named System - Legacy, and click on the red cross to enable the legacy plugin.
Once this has been enabled, any Joomla 1.0 template, component, module or mambot can be used on your Joomla website. As we have already said, the legacy plugin does introduce additional overhead, and should be used with caution. If possible, always use Joomla 1.5 components and avoid using the Legacy plugin.