Hi all,
After upgrading to 1.2 version, you must force the system to refresh the AU plugin list. (We missed it in 1.2 installer).
To force the system to relist plugins, open a Terminal application (in /Application/Utilities/Terminal) and type this command :
touch /Library/Audio/Plug-Ins/Components/
Then Logic should correctly open the graphical interface.
Nicolas,
ARTURIA