To turn on legacy support in Joomla 1.5 follow the below steps.
- Joomla Admin:Login to the Joomla admin by visiting http://yourdomain.com/administrator
- Open Plugin Manager:Click on Extensions in the top navigation and choose Plugin Manager from the drop down.
- Enable System – Legacy:Now visit page 2 of the plugins and click the red X for System – Legacy which will enable this module that provides support for Joomla 1.0 extensions. You can verify you have turned the module on by verifying the red X is now a green check mark.
That’s it. You can now install extensions from the previous version tree of Joomla.