When trying to edit or add menu item in Menu Manager, I have lost the GUI interface and all of the functionality.
Just updated to Joomla! 3.4.4 Stable [ Ember ] 8-September-2015 21:30 GMT and noticed the problem after the upgrade.
Any thoughts? I'm running RocketTheme Gantry framework on the site and have no trouble before the upgrade.
The screenshot you posted make me think that there must be a Fatal Error somewhere. Enable
error_reporting to see if any exists and where it comes from.
Most likely it will be an outdated extension, and by updating or uninstalling/removing it, it will resolve your issue.
Thanks. I've tried that out, however, when I check the front end I'm not seeing any errors. Is there somewhere else I can check for outdated extensions?