To get things working, the following packages need to be installed:
sudo apt install ubuntu-gnome-desktop gnome-shell gdm3
Optionally, you may also want to install
gnome, although this does not seem necessary if
gnome-shell has been installed. Hibernation did not work with lightdm, hence the need to install gdm through the package
But then there was also a need to reinstall nvidia proprietary drivers Following instructions of http://ubuntuhandbook.org/index.php/2015/01/install-nvidia-346-35-ubuntu-1404/ with slight modifications:
remove the current nvidia driver running
sudo apt purge nvidia-* && sudo apt autoremove
note the version of the nvidia driver you're removing, say
blacklist nouveau by opening
/etc/modprobe.d/blacklist-nouveau.conf with your favourite editor and inserting
options nouveau modeset=0
alias nouveau off
alias lbm-nouveau off
kernel nouveau (not sure whether this is necessary, though, but it does not seem to do harm to the installation)
echo options nouveau modeset=0 | sudo tee -a /etc/modprobe.d/nouveau-kms.conf
sudo update-initramfs -u
Reboot the computer and login to a terminal without display manager, e.g., CTRL+ALT+F1. Unfortunately, the display manager has been started already (still available under CTRL+ALT+F7), thus the service need to be stopped
sudo service lightdm stop
Activating gdm (
gdm3) as default display manager.
sudo dpkg-reconfigure gdm3
This will return an error saying that the service has not been started and hence the display manager could not be switched. No worries, the switch will be carried out upon reboot.
Re-installing the nvidia driver that has been removed earlier, where xyz is the version that was uninstalled under the first step.
sudo apt install nvidia-xyz
Reboot your system
sudo shutdown -r now
This made me have a completely functional system with
gnome-shell desktop and
gdm display manager. Bonus was a fully operational
hibernate. Hope this helps.