Kubuntu Forums - Kubuntu 26.04 Resolute Raccoon (LTS)

[Pre-Install]Can't install Kubuntu bootloader

sevenfourtyeight — Mon, 20 Jul 2026 22:26:58 GMT

Completely new to Linux (or at the very least installing it from scratch). I created a USB boot drive with Rufus (and later balenaEtcher) and tried to install Kubuntu onto my Asus laptop. Sadly I was hit with error code 1. Manually setting a partition for the EFI and disabling Secure Boot didn't help either. Any solutions?

[Pre-Install]cant do min install

elliot13458 — Mon, 20 Jul 2026 22:03:52 GMT

I tried installing lts on external hard drive usb. but on minimal install it gives this error. I installed from live iso on ventroy

Command DEBIAN_FRONTEND=noninteractive apt-get -y --purge remove kmahjongg kmines kpat ksudoku skanlite skanpage okular libreoffice* kdeconnect krdc neochat elisa haruna vim snapd partitionmanager usb-creator* plasma-welcome kde-config-tablet plasma-welcome finished with exit code 100.
Output:
Reading package lists...
Building dependency tree...
Reading state information...
Package 'libreoffice-core-nogui' is not installed, so not removed
Package 'libreoffice-base' is not installed, so not removed
Package 'libreoffice-base-drivers' is not installed, so not removed
Package 'libreoffice-base-nogui' is not installed, so not removed
Package 'libreoffice-calc-nogui' is not installed, so not removed
Package 'libreoffice-draw-nogui' is not installed, so not removed
Package 'libreoffice-evolution' is not installed, so not removed
Package 'libreoffice-filter-mobiledev' is not installed, so not removed
Package 'libreoffice-gnome' is not installed, so not removed
Package 'libreoffice-impress-nogui' is not installed, so not removed
Package 'libreoffice-l10n' is not installed, so not removed
Package 'libreoffice-l10n-4.3' is not installed, so not removed
Package 'libreoffice-l10n-4.4' is not installed, so not removed
Package 'libreoffice-librelogo' is not installed, so not removed
Package 'libreoffice-math-nogui' is not installed, so not removed
Package 'libreoffice-report-builder' is not installed, so not removed
Package 'libreoffice-sdbc-firebird' is not installed, so not removed
Package 'libreoffice-sdbc-mysql' is not installed, so not removed
Package 'libreoffice-sdbc-postgresql' is not installed, so not removed
Package 'libreoffice-wiki-publisher' is not installed, so not removed
Package 'libreoffice-writer-nogui' is not installed, so not removed
Package 'libreoffice-help' is not installed, so not removed
Package 'libreoffice-help-5.2' is not installed, so not removed
Package 'libreoffice-sdbc-hsqldb' is not installed, so not removed
Package 'libreoffice-style-andromeda' is not installed, so not removed
Package 'libreoffice-style-crystal' is not installed, so not removed
Package 'libreoffice-style-galaxy' is not installed, so not removed
Package 'libreoffice-style-hicontrast' is not installed, so not removed
Package 'libreoffice-style-tango' is not installed, so not removed
Package 'libreoffice-writer2latex' is not installed, so not removed
Package 'libreoffice-writer2xhtml' is not installed, so not removed
Package 'libreoffice-pdfimport' is not installed, so not removed
Package 'libreoffice-avmedia-backend-vlc' is not installed, so not removed
Package 'libreoffice-filter-binfilter' is not installed, so not removed
Package 'libreoffice-mysql-connector' is not installed, so not removed
Package 'libreoffice-avmedia-backend-gstreamer' is not installed, so not removed
Package 'libreoffice-dev' is not installed, so not removed
Package 'libreoffice-gtk2' is not installed, so not removed
Package 'libreoffice-gtk3' is not installed, so not removed
Package 'libreoffice-kde4' is not installed, so not removed
Package 'libreoffice-kde5' is not installed, so not removed
Package 'libreoffice-kf5' is not installed, so not removed
Package 'libreoffice-officebean' is not installed, so not removed
Package 'libreoffice-qt5' is not installed, so not removed
Package 'libreoffice-texmaths' is not installed, so not removed
Package 'libreoffice' is not installed, so not removed
Package 'libreoffice-java-common' is not installed, so not removed
E: Unable to locate package skanlite
E: Unable to locate package krdc

[Post-Install]Broken disk?

nilsA — Fri, 17 Jul 2026 21:39:17 GMT

On one of tree old PCs, after a week or so, the install is broken.

It boots into:

GNU GRUB version 2.14
Minimal BASH-like line editing is supported
...
...''

grub>

When I do

I get

(hd0) (HD0,mscos|) (HD0,msdos2) (HD0, msds3) (hd0, mosdos4)

But when I do

ls (msdos0)

I get

Device hd0: No known filesystem detected - sector size 512B - Total size 488386584KiB

And the PC will not boot from CD or USB, whatever I do in the BIOS.

Is the disk bad? OR can I rescue this?

[System]How do you troubleshoot a freeze-up?

Shibblet — Wed, 15 Jul 2026 22:57:16 GMT

This has happened quite a few times on me now. Just a freeze-up in the middle of doing things... Mouse stopped moving, and I had no choice but to hard-boot the computer.
It's usually not a big deal, I just deal with it and move on... but now that it seems to be happening more frequently... and moreso, that I really don't even know how to begin to troubleshoot a "freeze-up."

[Software]HTTP_PROXY variable for specific application - please review

boospy33 — Wed, 15 Jul 2026 17:56:41 GMT

Hello all,

I'm using SSL deep inspection through firewalls here. It works reasonably well. The only problem is when applications do things that can't be allowed by any rule, and there's no way to configure a proxy for them. For example, Steam.
So I've been experimenting with some Bash variables. My startscript:

Code:

#!/bin/bash
export http_proxy=http://fw66.tux.lan:8081
export https_proxy=http://fw66.tux.lan:8081
export HTTP_PROXY=$http_proxy
export HTTPS_PROXY=$https_proxy
export no_proxy=localhost,127.0.0.1
/usr/games/steam

And the whole thing actually seems to work very well. The firewall log confirms this, too.

My question is what do I need to watch out for to make sure that another application doesn't accidentally go through the proxy when it's not supposed to? Are there situations where this could happen?

Thanks

[Post-Install]Keyboard and mouse not working post installation of 26.04 (after upgrade from 25.04)

notAProgrammer — Tue, 14 Jul 2026 16:26:38 GMT

I updated from 25.04 or 25.10 to 26.04, and now my in built keyboard and mouse aren't working. They are however, working in the grub menu.In addition, the power button is correctly turning the system off.

I have two kernels - 7.0.0-27-generic - 6.17.0-40-generic. Trying to boot into the recovery mode (graphical) of the older 6.17.0-40 still leaves me with the same problem in the graphical interface. However, in recovery mode during terminal usage as root, I'm able to perform all standard I/O operations.

Any advice on what to do next?

[SOLVED]Failure when attempting to update kernel from 7.0.0-22-generic (64-bit) to 7.0.0-27-generic

jrwatts — Sun, 12 Jul 2026 21:01:26 GMT

I'm getting an error when trying to update the kernel:

Code:

Setting up linux-image-7.0.0-27-generic (7.0.0-27.27)…
Setting up linux-headers-7.0.0-27-generic (7.0.0-27.27)…
/etc/kernel/header_postinst.d/dkms:
Sign command: /usr/bin/kmodsign
Signing key: /var/lib/shim-signed/mok/MOK.priv
Public certificate (MOK): /var/lib/shim-signed/mok/MOK.der

Autoinstall of module hid-xpadneo/v0.9-222-gcd25680 for kernel 7.0.0-27-generic (x86_64)
Building module(s)...(bad exit status: 2)
Failed command:
make -j12 KERNELRELEASE=7.0.0-27-generic -C '/lib/modules/7.0.0-27-generic/build' M='/var/lib/dkms/hid-xpadneo/v0.9-222-gcd25680/build/src' VERSION='v0.9-222-gcd25680' modules
ERROR (dkms apport): binary package for hid-xpadneo: v0.9-222-gcd25680 not found

Error! Bad return status for module build on kernel: 7.0.0-27-generic (x86_64)
Consult /var/lib/dkms/hid-xpadneo/v0.9-222-gcd25680/build/make.log for more information.

Autoinstall on 7.0.0-27-generic succeeded for module(s) openrazer-driver.
Autoinstall on 7.0.0-27-generic failed for module(s) hid-xpadneo(10).

Error! One or more modules failed to install during autoinstall.
Refer to previous errors for more information.
run-parts: /etc/kernel/header_postinst.d/dkms exited with return code 1
dpkg: error processing package linux-headers-7.0.0-27-generic (--configure):
 old linux-headers-7.0.0-27-generic package postinst maintainer script subprocess failed with exit status 1
dpkg: dependency problems prevent configuration of linux-headers-generic:
 linux-headers-generic depends on linux-headers-7.0.0-27-generic; however:
  Package linux-headers-7.0.0-27-generic is not configured yet.

dpkg: error processing package linux-headers-generic (--configure):
 dependency problems - leaving unconfigured
dpkg: dependency problems prevent configuration of linux-generic:
 linux-generic depends on linux-headers-generic (= 7.0.0-27.27); however:
  Package linux-headers-generic is not configured yet.

dpkg: error processing package linux-generic (--configure):
 dependency problems - leaving unconfigured
No apport report written because the error message indicates its a followup error from a previous failure.
       No apport report written because the error message indicates its a followup error from a previous failure.
              Processing triggers for linux-image-7.0.0-27-generic (7.0.0-27.27)…
/etc/kernel/postinst.d/dkms:
Sign command: /usr/bin/kmodsign
Signing key: /var/lib/shim-signed/mok/MOK.priv
Public certificate (MOK): /var/lib/shim-signed/mok/MOK.der

Autoinstall of module hid-xpadneo/v0.9-222-gcd25680 for kernel 7.0.0-27-generic (x86_64)
Building module(s)...(bad exit status: 2)
Failed command:
make -j12 KERNELRELEASE=7.0.0-27-generic -C '/lib/modules/7.0.0-27-generic/build' M='/var/lib/dkms/hid-xpadneo/v0.9-222-gcd25680/build/src' VERSION='v0.9-222-gcd25680' modules
ERROR (dkms apport): binary package for hid-xpadneo: v0.9-222-gcd25680 not found

Error! Bad return status for module build on kernel: 7.0.0-27-generic (x86_64)
Consult /var/lib/dkms/hid-xpadneo/v0.9-222-gcd25680/build/make.log for more information.

Autoinstall on 7.0.0-27-generic succeeded for module(s) openrazer-driver.
Autoinstall on 7.0.0-27-generic failed for module(s) hid-xpadneo(10).

Error! One or more modules failed to install during autoinstall.
Refer to previous errors for more information.
run-parts: /etc/kernel/postinst.d/dkms exited with return code 1
dpkg: error processing package linux-image-7.0.0-27-generic (--configure):
 old linux-image-7.0.0-27-generic package postinst maintainer script subprocess failed with exit status 1
No apport report written because MaxReports is reached already
                                                              Errors were encountered while processing:
 linux-headers-7.0.0-27-generic
 linux-headers-generic
 linux-generic
 linux-image-7.0.0-27-generic
Error: Sub-process /usr/bin/dpkg returned an error code (1)

It looks like there's a problem with the `xpadneo` driver for my Xbox controller...does anyone know if this driver is still useful (I installed it years ago and it's remained through various upgrades)? I have a suspicion that I definitely don't need it when running games through Steam, but it may still be necessary for other games?

[Post-Install]My vintage gaming laptop dosn't appear to work properly

steve7233 — Sun, 12 Jul 2026 16:49:38 GMT

My system appears to be badly broken on this about 17 y/o gaming/laptop that runs DirectX 10. I suspect Wayland. I switched to X11, but I suspect Calmerus, or however the installer is spelled, may not be able to install properly via Wayland. Is there a way to install via X11, or maybe a switch in 24.04 at boot time, or maybe some other switch is needed? I wanted to play Banished, which has both a 32-bit and a 64-bit main executable file. I eventually got Banished to work, but it doesn't work very well, and I suspect it would work better on a properly built system. For one thing, if I type ALT+F2, the system reports that the signal was sent, but for an unknown reason, Krunner isn't responding! HP Pavilion 1030 Gaming/laptop dv6-us. A Core2 Duo and a 4500 MHD Integrated graphics. 4 GB of 2 DIMM modules, which are DDR2. All Intel parts. If you need more information, I will try to get it, but this is a discontinued product, so HP has taken down almost all info on it from their website.

EDIT: I forgot to add that I already downloaded 24.04 because I suspect I may need to downgrade from 26.04. I haven't written it to the USB yet, as that would wipe out the 26..04. I am waiting for a response to this thread to see what switch or switches I should use and which version I need to reinstall, or maybe there is a way to fix my broken system. The installer said that Kubuntu is designed to work on old machines, but it also said 8 years, and this machine is twice that age.

[Desktop]KDE Plasma 6.6.6 "the number of the Konqi" available in Kubuntu Backports

Schwarzer Kater — Fri, 10 Jul 2026 20:54:15 GMT

Above-mentioned updates for our preferred desktop environment are now availabe for Kubuntu 26.04 LTS in the Kubuntu Backports PPA.

Here is the link to the changelog for KDE Plasma 6.6.6: https://kde.org/announcements/change...6/6.6.5-6.6.6/

As far as I know Plasma 6.6.6 is the final release for Plasma 6.6 - also see Schedules/Plasma 6 (https://community.kde.org/Schedules/Plasma_6).

Again, thank you very much to the Kubuntu developers for providing this!

The Kubuntu Backports PPA contains "backports of new versions of KDE Platform, Plasma and Applications as well as major KDE apps for Kubuntu."

You can find the instructions how to add the Kubuntu Backports PPA directly on the website (Kubuntu Backports PPA), but here they are again:

Open the Konsole terminal emulator and enter

sudo add-apt-repository ppa:kubuntu-ppa/backports
(and confirm the addition with [Return])
sudo apt update

After this any future updates that the Kubuntu Backports PPA provide for your Kubuntu 26.04 LTS will be automatically installed when you update your system.

So now you can install the new Plasma packages e.g. by entering

sudo apt full-upgrade

and afterwards

reboot

As always I strongly recommend that you have prepared some way to revert your system to a previous state if something goes wrong, e.g.:

One can use ppa-purge (installed by default in Kubuntu 26.04 LTS) to get rid of the Kubuntu Backports' packages again.
Or use a Timeshift system backup.
Or use LVM/ext4 with snapshots or btrfs with snapshots as your file system.
Or use a Clonezilla volume backup.
Or …

[Post-Install]Udev prevents any attempts to sutdown that epermental WoW64 crap on very old Laptops

steve7233 — Wed, 08 Jul 2026 04:17:05 GMT

UDEV keeps failing at monitor creation, causing the winsever to completely crash! This prevents the game from even starting, which is nonsense, as the computer is designed for DirectX 10. Wow64 won't work because there is zero Vulkan support. The laptop is simply too old, so I need Wow64 to step aside and allow the machine's graphics hardware to do all the heavy lifting. I think UDEVs problem is it is way to agressive at querying the USB system for mobo status. I have all three USB ports with wireless USB dongles, all Logitech. One dongle is for a wireless headphone/mic. The other two are for my wireless keyboard and wireless mouse. HP Pavilion 1030 dv6-us. It uses an Intel Core2 Duo and an Intel GMA 4500 HD for integrated graphics. Also, OpenGL 2.1. The Game is Banished, which played just fine on this laptop/gaming PC back in 2014 using the then-current Xubuntu. I was distro hopping to find something that worked until me and the Google AI figured out that the window manager wasn't the issue; it's getting mordern wine/Proton to let the hardware run the graphics engine instead of using DKVK. So I decided to switch back to Kubuntu to get KDE/Plasma again, only to discover that Microslop syndrome was taking over the Ubuntu developers' minds! I thought Ubuntu was supposed to be designed to allow users to do what they want with their own machines as long as its leagal.

[Network]Netplan vs Network Manager for static IP

TwoFistedJustice — Tue, 07 Jul 2026 00:01:01 GMT

In 24.04 when I entered the command `nmcli connection show` I was shown a list of UUIDs drawn from the files stored at `/etc/NetworkManager/system-connections/someUUID.nmconnection`

Now in 26.04 those files are gone, but the command still shows me the same old list.

Some digging found .yaml files with the info I needed at `/etc/netplan/90-NM-someUUID.yaml`

If I want to set IP addresses and such do I still use `nmcli connection modify [args]`?

Or has that been replaced, and if so what is/are the command(s) I need to learn to use?

[SOLVED]Upgrade tries to remove essential apps like Konsole and Dolphin

GGKazz — Mon, 06 Jul 2026 12:59:09 GMT

Hello all,
I'm trying to upgrade from Kubuntu 25.10 to 26.04 LTS however the upgrade removes all kinds of essential apps like Konsole or Dolphin.

Code:

Remove (was auto installed) apport-core-dump-handler dolphin
  dolphin-plugins elisa gwenview haruna kate kde-spectacle kdeconnect
  konsole konsole-kpart libasound2-plugins
  libgstreamer-plugins-good1.0-0 libgusb2 libgvc6 libk3b-extracodecs
  libkf6texteditor-katepart libonnxruntime1.21 libplasma6
  libplasmaquick6 libqt6multimediawidgets6 libreoffice-kf6
  libreoffice-qt6 mesa-va-drivers mesa-va-drivers:i386
  mesa-vdpau-drivers mesa-vdpau-drivers:i386 neochat okular
  packagekit-tools phonon4qt5-backend-vlc phonon4qt5settings
  plasma-widgets-addons python3-fuse python3-sip
  qml6-module-org-kde-kirigamiaddons-labs-components
  qml6-module-qttexttospeech qt6-speech-speechd-plugin
  sddm-theme-breeze xwaylandvideobridge

A few weeks ago I did the upgrade and did not pay enough attention so after the upgrade I couldn't access my files or open de terminal. I figured I'd try again later so I reverted back using Timeshift. But now I have to upgrade in a few days so I'd like to be able to resolve the issue.

My system information:

OS: Kubuntu 25.10 (Questing Quokka) x86_64
Host: B850M GAMING X WIFI6E (Default string-CF-WCP-ADO)
Kernel: Linux 6.17.0-40-generic
Uptime: 1 hour
Packages: 2610 (dpkg), 6 (flatpak), 14 (snap)
Shell: bash 5.2.37
Display (Q27P1B): 2560x1440 @ 60 Hz in 27" [External]
Display (LG ULTRAGEAR): 2560x1440 @ 180 Hz in 27" [External, HDR] *
DE: KDE Plasma 6.4.5
WM: KWin (Wayland)
WM Theme: Breeze
Theme: Breeze (Light) [Qt], Breeze [GTK2/3]
Icons: Papirus-Dark [Qt], Papirus-Dark [GTK2/3/4]
Font: Noto Sans (10pt) [Qt], Noto Sans (10pt) [GTK2/3/4]
Cursor: breeze (24px)
Terminal: konsole 25.8.1
CPU: AMD Ryzen 7 9800X3D (16) @ 5.27 GHz
GPU: AMD Radeon RX 9070 XT [Discrete]
Memory: 3.79 GiB / 30.96 GiB (12%)
Swap: 0 B / 512.00 MiB (0%)
Disk (/): 561.59 GiB / 1.79 TiB (31%) - ext4

Let me know if you need any more information. Thank you.

[Post-Install]Headset USB-Dongle is not recognized after boot

Wobbelblob — Sun, 05 Jul 2026 06:51:00 GMT

So, a curious problem that has followed me over more than one OS. My Corsair Virtuoso XT headset has a wireless USB Dongle. But for some time now, the headset (or the dongle) doesn't activate directly after a boot. I need to reinsert it after the boot. That always fixes the problem. I first thought that was an issue with my Bazzite which has produced more than one curious issue by now. But after (fully) switching to Kubuntu yesterday, the problem persists, which is weird. Any ideas how to fix it?

What I do know is that the headset doesn't even show with

Code:

lsusb

at all. This is the result I get before reinserting it:

Code:

Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 004 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 005 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 006 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 007 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 007 Device 002: ID 2516:0047 Cooler Master Co., Ltd. MasterKeys Pro L
Bus 007 Device 003: ID 067b:2586 Prolific Technology, Inc. USB 2.0 Hub            
Bus 007 Device 004: ID 2357:0604 TP-Link TP-Link UB500 Adapter
Bus 007 Device 005: ID 3837:1012 wch.cn MCHOSE MagDock
Bus 007 Device 006: ID 3837:100b RealTek MCHOSE A7 V2 Ultra+
Bus 008 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub

and directly after I get it to activate:

Code:

Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 001 Device 006: ID 1b1c:0a64 Corsair CORSAIR VIRTUOSO XT Wireless Gaming Receiver
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 004 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 005 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 006 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 007 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 007 Device 002: ID 2516:0047 Cooler Master Co., Ltd. MasterKeys Pro L
Bus 007 Device 003: ID 067b:2586 Prolific Technology, Inc. USB 2.0 Hub            
Bus 007 Device 004: ID 2357:0604 TP-Link TP-Link UB500 Adapter
Bus 007 Device 005: ID 3837:1012 wch.cn MCHOSE MagDock
Bus 007 Device 006: ID 3837:100b RealTek MCHOSE A7 V2 Ultra+
Bus 008 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub

[SOLVED]After a system update within 26.04 Steam refuses to run even after commands for namespace

MichaelEber — Sun, 05 Jul 2026 02:52:06 GMT

As soon as it was available i installed Kubuntu 26.04. I have had everything working without any issues, including running Steam. A day or two ago I had an update that I ran and at the end of the update it stated I had to restart in order to complete the install. I must assume that meant some operating system files had to be dealt with in that update and I restarted my system. After that, the next day I noticed I didn't have Steam running so I started it and got an error:

Steam now reqwuires user namespaces to be enabled.

This requirement is the same as for Flatpak, which has more detailed information available:
https://github.com/flatpak/flatpak/w...e-requirements.

First I tried to make send of that and got lost. So I googled how to do this and followed the directions.

FIRST:
echo 'kernel.unprivileged_userns_clone=1' | sudo tee /etc/sysctl.d/10-user-namespaces.conf sudo sysctl -p /etc/sysctl.d/10-user-namespaces.conf

after which I did this:
If you are on Ubuntu 24.04, you may also need to disable AppArmor restrictions by creating /etc/sysctl.d/60-apparmor-namespace.conf with the content kernel.apparmor_restrict_unprivileged_userns=0, then applying it via sudo sysctl -p /etc/sysctl.d/60-apparmor-namespace.conf.

Then I finally tried the last step:
sudo setcap -r $(which bwrap) It stated that ther is no remove command
sudo chmod u+s $(which bwrap) Seemed to run without a problm

After all of this I went to launch Steam and it flushed itself down the toilet once again!!! HELP

[Post-Install]Keyboard Backlighting

Steve The Noob — Sat, 04 Jul 2026 22:48:38 GMT

I have recently installed Kubuntu 26.04 LTS on a new Lenovo Thinkbook 16 Gen 8 laptop. Everything was going great ... until early yesterday morning.

After some early AM random surfing, I shutdown the laptop (I did not put it in 'sleep' mode).

However, then the back-lighting for every key on the keyboard lit up !! The laptop did shutdown, but the back-lighting remained on. I attempted to log back in, aiming to shut the system down again but could not do so. Pressing the power button did nothing; holding the power button down for an extended period did nothing - the system would not re-boot. I went back to bed, figuring that everything would sort itself out by morning.

However, the status was exactly the same when I awoke later that morning (5am). All back-lighting was still on. I should note that I normally keep the power plugged-in when at home. I decided to unplug the power supply and let the battery run-down to zero, hoping this would solve the issue. Fortunately it did. When the battery had reached zero, I plugged the power in again and was then able to turn the laptop on.

I used AI (Claude) to research the problem. Aided by the AI, I checked the relevant page for my device on the Lenovo support website, as well as the boot logs for my device. The AI was able to determine that the event was related to a somewhat uncommon EC issue.

I am not entirely certain if this was a 'Kubuntu' problem or a 'Lenovo' problem. The problem has not re-occurred, even after multiple re-boots. Additionally, I had been running Kubuntu for several days before the issue.

I would appreciate if someone who knows Kubuntu more than I (ie: most of you !!) could shed some light on this issue.