Fix Ubuntu upgrade v16 to v18

I tried to update Ubuntu v16 to v18 in VMWare Workstation, only to be stuck at the “login” screen. In fact, there was no chance for login, because the computer was not displaying the means to do so. Technically, the machine was responding, because it was still somewhat moving the pointer on mouse moves, but clicking and using the keyboard produced no useful feedback.

I managed to salvage Ubuntu v18, but at one point, I was very close to revert to a previous snapshot.
All credit for the salvage goes to this resource:

and to an answer by user
Caleb McKay

Basically, do as follows:

  1. boot Ubuntu in recovery mode
  2. drop to root shell prompt
  3. edit GDM3’s configuration by entering the command
    sudo nano /etc/gdm3/custom.conf
  4. while editing, just change
  5. save your edit (CTRL^O followed by CTRL^X)
  6. restart the machine

In my case, this solution worked: Ubuntu v18 booted without further issues.

ubuntu_16_to_18_fix_01.png (image/png)


ubuntu_16_to_18_fix_02.png (image/png)


ubuntu_16_to_18_fix_03.png (image/png)


ubuntu_16_to_18_fix_04.png (image/png)


Technical Details