Using FX 8 b123.
The attached code doesn't behave as expected:
- when opening Main menu in the System menu bar its content is all disabled and you do not see at all the sub-menus.
- if you open the default "java" menu left to it then open again the Main menu you might see the content enabled, but still sub-menus are missing.

If you run the same code with setUseSystemMenuBar(false) then it works like a charm, every 3 Menu under Main one are enabled and have their respective sub-menu containing each 6 MenuItem, all enabled and that you can select. That rocks as well on Win and Linux.