Kubuntu 16.04 failed upgrade (problem with xserver-xorg-video-all?)

Question

I'm trying to upgrade my Kubuntu Wily 15.10 computer but it fails.

I'm doing this:

$ sudo do-release-upgrade -m desktop

This is what I get:

Calculating the changes

Could not calculate the upgrade 

An unresolvable problem occurred while calculating the upgrade. 

This can be caused by: 
* Upgrading to a pre-release version of Ubuntu 
* Running the current pre-release version of Ubuntu 
* Unofficial software packages not provided by Ubuntu 

If none of this applies, then please report this bug using the 
command 'ubuntu-bug ubuntu-release-upgrader-core' in a terminal. 

I found this on /var/log/dist-upgrade/main.log:

2016-04-29 10:29:09,024 DEBUG need_server_mode(): run in 'desktop' mode, (because of key deps for 'kubuntu-desktop')
2016-04-29 10:29:16,112 DEBUG Installing 'xserver-xorg-video-all' (Distro KeepInstalledPkgs rule)
2016-04-29 10:29:16,559 ERROR Dist-upgrade failed: 'E:Unable to correct problems, you have held broken packages.'
2016-04-29 10:29:16,560 DEBUG abort called
2016-04-29 10:29:16,576 DEBUG openCache()
2016-04-29 10:29:16,576 DEBUG failed to SystemUnLock() (E:Not locked) 
2016-04-29 10:29:20,464 DEBUG /openCache(), new cache size 78719
2016-04-29 10:29:20,464 DEBUG enabling apt cron job

What can I do?

Answer 1

I could solved. I follow the advice from this answer: https://askubuntu.com/a/367329/483417

What I did was:

sudo apt-get remove xserver-xorg-video-all
sudo do-release-upgrade -m desktop

I waited for the upgrade ends and restarted the computer. After that, Kubuntu started with no problems. The graphics were configured too. I think that is because I have a nvidia graphic card and the driver upgrade reinstalled everything again, even xserver-xorg-video-all.

Finally, my Kubuntu is Xenial :-)