Have been running Ubuntu Mate 17.10 and just upgraded to 18.04 LTS. But after upgrading my monitor settings are all wrong and can't set the proper resolution. How can I resolve this?
I had this issue and first switched to nouveau driver which fixed my laptop's display, but did not allow me to connect a second monitor. I fixed that issue running:
sudo ubuntu-drivers devices
which showed that the nvidia driver was recommended.
driver : nvidia-driver-390 - distro non-free recommended
driver : xserver-xorg-video-nouveau - distro free builtin
So I then ran
sudo ubuntu-drivers autoinstall
which installed and used the nvidia driver.
sudo shutdown -r now
This is the post I followed to get those instructions.