This is a short howto on how to restore the default panel in Lubuntu 20.04.
Often, when playing around with a desktop environmnet, you just happen to break it. It's easier than you may think (or it's just me, i don't know).
This time the system panel was gone and i couldn't make it appear again.
Lubuntu, and its DE "LXQt" changed quite a bit in the last two years, so i couldn't find any solution on StackOverflow or on the official forum.
I've digged a bit into "~/.config" that in Linux is a standard location for user's configuration files and i've found a file called "panel.conf" that was updated exaclty when i had broken my DE. Bingo!
Usually user specific configuration files, are copied eventually modified from a system standard folter, so after having found the user configuration file, i've tried to find that configuration file on more generic locations like "/etc" or "/usr/share": I've found it under "/usr/share/lxqt/panel.conf".
Having found the file i thought it was the system default (spoiler: it was) i've tried to restore my configuration by overvriting the conf in my home folder with:
$ sudo cp /usr/share/lxqt/panel.conf ~/.config/lxqt/
After reboot my DE was back in businness!
I hope this small guide will be useful to you.