Ubuntu – How to make GDM the default display manager

display-managergdmlightdm

I believe my question says what I am trying to achieve.

Steps I tried to make gdm my default display manager:

sudo dpkg-reconfigure than select gdm as my default.
Edit /etc/X11/default-display-manager and change its content to
```
/usr/sbin/gdm
```

After the above two steps I logged out myself and after that when I see my login screen it still shows lightdm as my display manager.

What am I doing wrong here.?

You seem to have configured gdm correctly, but you did not actually stop lightdm. Logging out doesn't stop it.

After doing sudo dpkg-reconfigure gdm, you need to stop lightdm

sudo service lightdm stop

and start gdm

sudo service gdm start

Hope this helps.

Run the following in a terminal:

sudo apt-get update && sudo apt-get install lightdm

That should resolve your issue.

I've googled the content of gdm.log (whose contents CameronNemo asked me to post) and found out the solution in this link.

The problem was an invalid line in /etc/profile probably inserted during an update:

[[ -f "/etc/autopackage/paths-bash" ]] && . "/etc/autopackage/paths-bash"

I just commented this line and now GDM is working properly.