After Upgrade to Ubuntu 20.04: "Oh no! Something went wrong"

I upgraded to Ubuntu 20.04 today, choosing LightDM over gdm3 during the upgrade. During the upgrade I was asked if I wanted to keep or replace /etc/sane.d/dll.conf file. I decided for keeping it.

Now, without actively rebooting, the "Oh no! Something went wrong" screen appeared.

As I am still inexperienced with this kind of troubleshooting, I feel it wouldn't be safe to just try out answers from other threads that don't have exactly the same 'history'.

Solutions I read included Ctrl+Alt+F4 and trying to login and get more information from the command line (Oh no! Something has gone wrong on restart).

Is that safe to do? Ideally, I'd like to save my data that is stored on an encrypted harddrive before trying to fix errors. I'd like to avoid reinstalling the OS.

From reading other threads, I know this post may be criticised as not being precise enough or haven't tried enough, but really I cannot get more information from that white screen myself and don't want to risk ruining everything just to provide more information...

Thank you for your help!! :)

Edit: I have no idea if the problem is related to lvm2-activation-generator, as in Ubuntu 19.10 “Something has gone wrong” after update from 19.04 This and other solutions include booting from a live usb. Can I do this 'safely' by simply switching the laptop off at this stage? Do I have to do sth before?

This will go a long way toward making that "Oh no something went wrong!" sign go away. First, press Ctrl+Alt+F3 to trigger the CLI, and login. Execute the command:

sudo apt-get update && sudo apt-get dist-upgrade 

to continue upgrading. Your machine will install the missing resources, and finish upgrading, and then you just have to clean up and reboot:

sudo apt-get clean && sudo apt-get autoremove && sudo reboot

Best of luck!

I had the same issue while upgrading my Ubuntu 18.04 to Ubuntu 20.04. some of the packages got crashed up. Mainly it is showing due to interruption of dpkg operations while booting the system.

Here's what I did to resolve this problem.

Firstly, press Ctrl+Alt+F3 together in order to open the terminal, then enter your login credentials and execute these following commands given below:-

sudo apt-get update && sudo apt-get upgrade
sudo dpkg --configure -a
sudo apt-get clean && sudo apt-get autoremove
sudo reboot

This will resolve the problem of dpkg having been interrupted.

My question has been answered with the help of Ollie:

• sudo apt-get update returned

  Could not get lock /var/lib/apt/lists/lock. It is held by process 22027 (focal)
  

• I tried to identify the process with ps aux | grep -i apt and ps -aux | grep -iE "apt-get" which didn't work, but I could identify it with pgrep focal which gave me its process ID. I killed it with sudo kill <process_id>.

• do-release-upgrade worked for me only without the -y option. It returned

  There is no development version of an LTS available.
  To upgrade to the latest non-LTS development release
  set Prompt=normal in /etc/update-manager/release-upgrades
  

• Then I ran sudo apt-get upgrade -y and got the message 0 upgraded, 0 newly installed, 0 to remove and 1 not upgraded. The 1 not upgraded was an expired libc++1 package.

Rebooting the computer, Ubuntu 20.04 worked well.

I then installed the current version of this libc++1 package via Synaptic.

To solve this problem in my case, I used the recovery mode option in the GRUB menu and then selected the option to start a root shell. Then I ran these commands

apt-get update && sudo apt-get dist-upgrade
apt-get clean && sudo apt-get autoremove
apt-get remove nvidia-340 

I had wrongly installed this nvidia package that was causing my issues.