PROBABLY solved (at least on Ubuntu). The app to call from "Run" is "alacarte", and through it's possible to make "Preferences" visible again, and therefore it's possible again to call "alacarte" as LXDE Menu / Applications / Preferences / Main Menu. Is this t...
I relied too much on Ubuntu handholding and now I don't know where to do config file surgery. I was pruning the visible applications in the Main Menu configuration dialog. I saw two instances of a "Preferences" submenu, one in its "right" place, and another that (I think) was nes...