Hi i have issues in kubuntu 26.04 latest version

[happy_winter]

hi i have some issues in kubuntu 26.04 latest release. can you help

[claydoh]

Issues with Kubuntu/Ubuntu the distro, or with something in Plamsa specifically?

You will need to specify what your issues are.

[happy_winter]

I recently upgraded my laptop from Kubuntu 24.04 LTS to Kubuntu 26.04 and have since run into the following issues:

Switch User option missing: The “Switch User” option is no longer available in the new version.
System freeze after screen lock: If the screen stays locked for some time, the laptop freezes and becomes unresponsive.
Start menu missing: The Start Menu (Application Launcher), which was available in Kubuntu 24.04, is no longer visible.
I would like to confirm that these problems are not related to the hardware. The same laptop worked without any of these issues on Kubuntu 24.04. The system specifications are:

Processor: Intel Core i5
Memory: 8 GB RAM
Storage: 512 GB SSD
I would be grateful if you could help me resolve these issues. Please let me know if you need any further information.
Thanks & best regards, skn

[claydoh]

This may be more a distro issue, considering it is an upgrade. Plus 24.04-26.04 upgrades have not been officially turned on yet.

I still upgraded mine a couple of months back, but am not seeing your issues, personally, nor have I noticed similar on Kubuntu’s forum, as few there have forced the upgrade early.

But adding the missing Application Launcher to the panel is easy enough, the same as adding any widget to the panel in Plasma 5. Getting the launcher back would get you the Switch user option as well.

or it may be like this:

The Launcher settings has some options for this.

Is the system suspending after the screen is locked for a short time? This is the normal setup for this, usually. This sort of thing is most likely hardware/driver/kernel related. You might try using a different kernel from your Grub boot menu and see if there is any difference.

[happy_winter]

Hi, thank you for the suggestions. Let me observe this for a few days, and I’ll get back to you if the issue persists.

Regards,

happy winter

[happy_winter]

do you have any support email id so that i can email to your team or only this kind of forums.

[claydoh]

Community

[happy_winter]

Hi,

I observed a few issues in Kubuntu 26.04 and have attached a short video demonstrating them. I’ve listed the issues below:

1. Screen blinking after locking:
   The main issue is that if I lock the system for around 5 minutes, I am sometimes unable to enter the password again. The screen starts blinking, and I cannot type the password. After rebooting the system, it works normally again.
2. Switch User option:
   I’m still unable to locate the Switch User option in the new Kubuntu 26.04. Could you please guide me on how to enable or access this option?
3. Start Menu theme:
   The Start Menu theme does not seem to be working properly in Kubuntu 26.04.

I have uploaded the error details and the screen recording to the following Google Drive link:

kubuntu 26.04 errors – Google Drive

(hope the above google drive link will open without any issues, if not let me know.)

[claydoh]

A few things - you are using a custom theme here? The lock screen text box looks different. The stock Kubuntu theming does not show your characters as you type-- we can see your password in your video!!

You are missing a panel - there normally is one at the bottom of the screen. Is this intentional?

Your start menu has been switched from the default Application Launcher to the full-screen Application Dashboard. This does not seem to offer a Switch User option; I have no idea if this is a Plasma bug, or if this is just not included with this menu style.

You can switch to a different style, and there are also numerous third-party menu widgets you can install that might have options to show the Switch User button. To do this you probably need to re-add a panel so you can right-click on the start menu icon to switch it (right-click >> Edit Mode > Add Panel >> Default or Kubuntu)

Tghe blinking and broekn screen unlock is probsably related to your specific hardware’s suspend, your kernel, as well as your video card/driver. That will be more of a can of worms, so others with similar hardware hopefully have mentioned their experiences somewhere out there.

[happy_winter]

ok thanks for your input. let me observe for some more days and then get back to you.

[Alexandr_Drobyshevsk]

Hello. Yesterday I updated packages as well. And today can’t login into system. The Plasma just crashed

[Alexandr_Drobyshevsk]

So. I spent 2,5 hours with chat-gpt and deep seek to solve the issue. And finally I have resolved it. For people who will search for the same situation.

sudo apt purge fonts-katex

Helped me.

[happy_winter]

still the same issue still persist. you ofcoure helped me but you mentioned that you upgraded and found no issue. so posted here again. the other issues are not that important to me. but if i lock the screen the laptop is getting hang. each and every time i need to restart for this. i am scared that my os may corrupt due to this issue. so requesting to support. yes it is same as posted in kubuntu contact since if i lock the screen

if no other option works out i will do a clean install again since i did a upgrade directly from 24.04 to 26.04 using command prompt option

kubuntu 26.04 errors – Google Drive

[meven]

@Alexandr_Drobyshevsk

So. I spent 2,5 hours with chat-gpt and deep seek to solve the issue. And finally I have resolved it. For people who will search for the same situation.

sudo apt purge fonts-katex

Seems really indirect.
A font style shouldn’t be able to break the system.

This seems to hide a bug somewhere in the KDE stack, worth fixing.
Did you learn anything that could tell us where the issue was with fonts-katex ?

[claydoh]

Could some of these instances be from this Chrome bug that is involving font stuff?

Chromium

Chromium

[nite_route]

for the lock hang, next time it blinks grab a tty (Ctrl+Alt+F3) b4 rebooting:

-journalctl -b -p err --since “10 min ago” | tail -80
-coredumpctl info kscreenlocker_greet 2>/dev/null | tail -40

also in System Settings → Power Management, turn off suspend-when-locked for a bit. that combo freezes resume for me on some laptops.

if journal shows gpu reset / nvidia / i915 hang, say which gpu u have.

[michaell]

@happy_winter

1. The main issue is that if I lock the system for around 5 minutes, I am sometimes unable to enter the password again. The screen starts blinking, and I cannot type the password. After rebooting the system, it works normally again.

This sounds like a video driver issue. The easiest fix is to disable screen locking and be done with it: go to System Settings → Screen Locking → Lock screen automatically: Never

[Olivia]

I just booted up my computer and logged in and I have a totally blank screen. I have had nothing but trouble since the upgrade to 26.04. I have the latest neon on another PC and I’ve had no problems.

[h-pine]

Hello.

Are you using Chrome or a Chromium-based browser such as Brave?
If so, your issue might be related to the following posts:

Background briefly shows and plasma crashes: Plasmashell version 5.27.12

Oye, so after having delayed updates for a bit I finally performed all of my system updates only to discover a number of issues, the issue reported here only started after awhile. My issues started with my OrcaSlicer AppImage screens showing black and not rendering. At first I thought this was just an OrcaSlicer and system update conflict, but then after locking my machine and coming back later I found that my entire system had seemingly rebooted on it’s own. After logging in I too was faced w…

After logging in, the screen is black with only the mouse cursor visible

Summary / Solution The following command and Alexandr_Drobyshevsk’s post resolved the issue for me: sudo apt purge fonts-katex Details Yesterday, I updated Kubuntu on my AMD Ryzen 2200G system. After the update finished, I saw an icon prompting a system reboot. I clicked it, but a crash error appeared and the system wouldn’t reboot. I tried to open Konsole to restart via command line, but it crashed too. Shortly after, the system became completely unresponsive. I performed a hard reboot usi…

[happy_winter]

hi claydoh & h-pine,

thanks for your inputs. yes, i am using chrome browser. shall i uninstall and try it ? will it solve the issue. is this issue related to chrome browser?