Keyboard backlight Ubuntu 18.10 not working
Solution 1:
Open terminal and type, hit enter
sudo /etc/acpi/asus-keyboard-backlight.sh
It will turn on your asus laptop backlight.
This script comes with acpi-support package.
Solution 2:
I was having the same issue on my UX430, to fix it just update your kernel to 4.19. You don't get the on screen display but it does now at least work