[SOLVED] Ubuntu: No Desktop Environment

Suddenly Ubuntu's desktop did not work. A "startx" command died too. But I could log into the command shell. The cure was a reinstall:

sudo apt install --reinstall ubuntu-desktop

A few moments later everything went back to normal. 

Ubuntu and Logitech Gamer Keyboard

For years I used a terminal command in order to set the keyboard colors. But it's more practical to use Piper. For unknown reasons Piper would not show up in Ubuntu's software installer, however the solution was:

# sudo apt install piper

Ubuntu: Snap Upgrade

Do thou this in ye terminal:

snap-store --quit && sudo snap refresh snap-store