Looks like Opera may have moved to remove the title bar from the latest version. I'm cool with that but I have no menus.
My system settings keep the application menus in the title bar of that application (as opposed to the Mac style of keeping them at the top of the screen). Since Opera has no title bar (and I'm assuming this is by design based on some other changes) there is no place for the menus to exist. This would be just fine had they included an O menu (as they do in Windows), but they didn't.