System no longer sees any network connections

[MDuff]

Kubuntu 16.04 on Lenovo Thinkpad T450s
After a recent update was completed, the system froze and upon re-start it could not find any WiFi network. When connected by cable it could not find a cable connection. When I rebooted to Kubuntu 14.04 everything worked but when I booted back to 16.04 no network connections were visible.

There is no mention of this happening to anyone else that I could find.

Does anyone have any thoughts on this strange behavior?

[vinnywright]

boot to your preveous kernel ,,,,,,,,,to get back network,,,,,then run updates

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

it happened to me Tuesday .

VINNY

[Oderus]

How can i repair this issue from recovery terminal (using wifi) or from live cd? all of my kernals are effected. I know i just have to update but not sure how to go about it from recovery terminal or livecd.

[MDuff]

Nada Booting to previous kernel did not reveal network connections

boot to your preveous kernel ,,,,,,,,,to get back network,,,,,then run updates

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

it happened to me Tuesday .

VINNY

Tried going back to first kernel but still no network connections visible, wired or wi-fi.
Got fed up and am now doing a re-install of 16.04 and will see if it happens again.

[Oderus]

I booted from a livecd, mounted my filesystem, and used chmod to execute the command. After doing this, I get the same exact error. Screen shot included.

[Darin Miller]

This issue has an easy fix posted in the bug report (https://bugs.launchpad.net/ubuntu/+s...t/+bug/1569674)

Comment #39Ovidiu-Florin BOGDAN (ovidiu-florin):
sudo apt install libkf5networkmanagerqt6=5.18.0-0ubuntu1

then
killall plasmashell && plasmashell &

Fixed my issue!

[Oderus]

Thank You!

This issue has an easy fix posted in the bug report (https://bugs.launchpad.net/ubuntu/+s...t/+bug/1569674)

Comment #39Ovidiu-Florin BOGDAN (ovidiu-florin):
sudo apt install libkf5networkmanagerqt6=5.18.0-0ubuntu1

then
killall plasmashell && plasmashell &

Fixed my issue!

Darin, thank you very much, this did it for me. Any ideas if this package will be fixed or if theres a way to have update ignore it? Its already trying to reinstall itself xD Glad I ran into you on irc last night or i'd still be stuck!

Edit: I just removed the backports software source and its being ignored.

[Darin Miller]

Oderus,

Both 16.04 plasma-staging with plasma 5.6.3 and 16.10, plasma 5.6.4 are working fine. I suspect the networkmanager issue interim update fell through the cracks. The KDE developers are still moving lots of packages around which is creating havoc for the Kubuntu packing developers.

[siabost]

Thanks Darin/Oderus,

I also had this issue after an update two days ago. The workaround (downgrade) worked for me too. I wonder when it will be safe to do a full update again.

[woodsmoke]

MDuff's problem was the same to which I posted in another thread.
The fix worked but after restart did not get the sam error message but does not work.
required a bunch of autoremove.
A restart was stated as required.
killall did exactly that.
posting on a black screen.
woodsmoke

[woodsmoke]

please see my immediately previous post
fix worked before restart did not work after restart.
woodsmoke

[woodsmoke]

Notified of an update:

libkf5networkmanagerQT6(5-18.0-Oubuntu 1.2)

did not work in session
restart stll no network manager
now have the original situation and error message

woodsmoke

[woodsmoke]

I did Darin's fix again WITHOUT the killall.

I changed settings/desktopsession login and logout to "start with an empty session".

removed the ethernet cable.

restarted and wireless is back.

notified of the same update did NOT do the update and wireless works.

A situation which I forsee is that when the eventual fix arrives that people who have done this fix and have become accustomed to not doing the present update will not recognize that either a new update is available or just not do it.

Possibly a post here at the forum about the PARTICULAR line for the fix might be helpful.

woodsmoke

[woodsmoke]

An update as of this instant, for 8 items including:

libkf5networkmanagerqt6=5.18.0-0ubuntu1.2

note the "2"

worked, required a restart.

Thanks Darin for the workaround!

woodsmoke