Table of Contents
Sometimes, on some installation, attributes and types trees are not loaded.
If you're under Joomla! 1.5, check if you have installed the latest available version, and if the system plugin Mootools upgrade is activated.
To fix that, simply reload the page. Please note that JCE editor loads the plugin using an IFRAME, so you have to right click on the screen » this frame » reload this frame
You should disable all the plugins and try to enable them one by one: in this way you can understand who's conflicting with J4Schema.