Today, after upgrading kernel to 5.4.0-71.79 the boot process stopped.
I had to switch to the previous kernel (5.4.0-70.78), and all was OK.
No broken packages. No update needed, unless this:

Code: Select all

apt list --upgradable -a
Listing... Done
linux-modules-nvidia-460-generic/focal-security,focal-updates 5.4.0-71.79+1 amd64 [upgradable from: 5.4.0-70.78]
linux-modules-nvidia-460-generic/now 5.4.0-70.78 amd64 [installed,upgradable to: 5.4.0-71.79+1]


But I don't see how upgrade that...
And maybe it is not the problem.

I tried reinstalling the last kernel, but nothing changed.
What should I do?

It seems a problem of compatibility of nvidia drivers with the new kernel: see here.
Ubuntu problem or Nvidia problem? Who has to do something to fix it?

Have the same problem. Can't boot plasma-desktop on 5.4.0-71-generic. I have to start grub after reboot and select 5.4.0-70-generic and in this way it works fine.

I had something similar, don't remember with what kernel it happen (5.4.0-69 5.4.0-70 or 5.4.0-71).
But what I did is run this command that gave me the kernel files:
dpkg --list | egrep -i --color 'linux-image|linux-headers|linux-modules' | awk '{ print $2 }'

right not that command gives me:
linux-headers-5.4.0-70
linux-headers-5.4.0-70-generic
linux-headers-5.4.0-71
linux-headers-5.4.0-71-generic
linux-headers-generic
linux-image-5.4.0-70-generic
linux-image-5.4.0-71-generic
linux-image-generic
linux-modules-5.4.0-70-generic
linux-modules-5.4.0-71-generic
linux-modules-extra-5.4.0-70-generic
linux-modules-extra-5.4.0-71-generic

when I had the problem some of those files were missing. I think it was the linux-headers of the updated version that were missing.
In any case, I installed them, reboot and all is fine.
hope this helps.

New kernel upgrade from Ubuntu (compatible with nvidia): solved!