No possible way to install Ubuntu on Asus Zenbook UX433FN
I just solved this problem on my Zenbook UX533FD with Ubuntu 18.04.
It turns out update/upgrade will update the Intel related stuff and then crush the system
This is what I did:
In grub, choose Ubuntu, DON'T PRESS ENTER, press 'e', add dis_ucode_ldr
after the line start with Linux, then boot (press F10), should be bootable now.
Once booted, in terminal:
sudo apt install intel-microcode=3.20180312.0~ubuntu18.04.1
Then hold the package:
sudo apt-mark hold intel-microcode=3.20180312.0~ubuntu18.04.1
I have written a readme about the problems I have with this laptop. Hope it helps.