Did you install from npm as per the documentation or did you download it from somewhere else?
Are you saying the app won't ever start again or that you can't edit the config again once you get it to this state? Not seen that before.
You can manually edit the config in ~/.config/joplin/settings.json
Installing following the doc instructions fixed the problem! Thank you for the quick response and the solution! I am a fan of this application, so being able to edit with external editors is a huge plus.
The app would start but I could not edit a note because I could not switch back to the original editor.
I suspected this might be the case, I think the Ubuntu software app lists the flatpak (which isn't mainted by the Joplin team) and because of the sandboxing you would have to set other permissions first.