I had the same issue, having updated my Ubuntu partition to 18.04, ASUS K501UQ. I added "dis_ucode_ldr" after "quiet splash" and it worked, both when temporarily added using 'e' with GRUB, and permanently added by gediting /etc/default/grub.
I would like to thank everybody on this thread, you really saved my bacon.
I had the same issue, having updated my Ubuntu partition to 18.04, ASUS K501UQ. I added "dis_ucode_ldr" after "quiet splash" and it worked, both when temporarily added using 'e' with GRUB, and permanently added by gediting /etc/default/grub.
I would like to thank everybody on this thread, you really saved my bacon.