I have just installed Ubuntu 18.04 LTS from mini.iso using Ethernet/cable.
Then I have installed MATE desktop to it by
sudo apt-get install ubuntu-mate-desktop^.
But the NetworkManager tray icon/nm-applet says that Ehernet Network — device not managed:
What is the simplest method to setup the system to use NetworkManager back?
Note: please do not close this as duplicate - I need complete reproducible solution in one place.