How to enable and switch on legacy mode in Joomla 1.5? In early beta release of Joomla! 1.5 (e.g. beta1 and beta2), option to enable and turn on the legacy mode is part of the Global Configuration. However, in the latest RC release of Joomla and final gold release of Joomla 1.5, the legacy mode support has been moved to the plugin manager. Thus to enable the legacy mode, simply follow steps below to publish the Legacy Mode plug-in.
1. Login to Joomla 1.5 Site Administrator panel.
2. Mouse over Extensions in the main horizontal menu, then click on Plugin Manager.
3. Locate plugin named System – Legacy, and then click on the check box in front of it.
4. Click on Enable button.