Taskbar not visible with Lubuntu under VirtualBox

Support and Help
1

Ubuntu Support Template

Ubuntu Version:
Lubuntu 26.04 LTS

Desktop Environment (if applicable):

LXQT

Problem Description:
I have been running Lubuntu under VirtualBox for about two years, without issue.

I don’t remember what version I had before, but recently I upgraded to 26.04.

And after this, the taskbar in the Desktop Environment is transparent (sort of - details below). See for example this screenshot.

image
image1181×832 51.9 KB

This is scaled, so there is no risk that the image is truncated and the taskbar below the bottom limit.

The transparency itself is also weird, because it is delayed and… freezing (for lack of a better word). See this example:

image
image1181×339 61.1 KB

Here, I moved the browser window below the taskbar. For several seconds after that, the taskbar area was just showing the wallpaper. After a few seconds, it showed the corresponding area of the browser. After I moved the browser again, the image remained frozen for several seconds.

I upgraded VirtualBox to the latest version (7.2.8 as of this writing) and made sure to install the extensions, more than once, both from the VB menu, and via manual commands from the mounted CD. The issue persisted.

One thing which I am noticing is that every several seconds, the desktop itself seems to flinch. I have a feeling it’s some kind of process failing and restarting, but I don’t know how to find details.

Relevant System Information:

VirtualBox 7.2.8 running under Windows Server 21H2

Screenshots or Error Messages:
I would provide more, but honestly don’t know where to start.

I had a look in dmesg and journalctl, but I don’t know what from there may be relevant to this. Nothing stood out to me.

What I’ve Tried:

I’ve played around with literally all the settings in the config that have anything to do with the display. Resolution, refresh frequency, themes, widget styles, GTK styles, , session settings (restarted the X compositor, restarted the Desktop, restarted the Panel) etc. I lost track of all I did.

I changed the DE to LightDM. After that, the taskbar becomes visible, but the desktop is ugly in various ways.

Before Posting:
:mag: Please check if similar issues have already been reported and resolved.

2

IIRC from my previous endeavors with VirtualBox, the guest extensions require kernel modules. How did you install them?

There are also some packages in the Ubuntu archive:

apt search -n virtualbox

But, if my vague memory serves me right, you need to version match those to the actual VB on the host.

3

I tried both methods more than once:

  • VirtualBox menu > Devices > Upgrade guest additions
  • From the command line.
    • Mount the CD using VirtualBox menu > Devices > Insert Guest Additions CD image…
    • Then, cd to where it’s mounted
    • There, run ./VBoxLinuxAdditions.run

Indeed, as I understand, this installs one or more dkms modules, but I don’t know details about what they do.

I followed your suggestion and did find some apt packages for virtualbox. But unfortunately I don’t know which of them might help in this case.

boinc-virtualbox/resolute 8.2.9+dfsg-1build1 amd64
  metapackage for virtualbox-savvy projects

unity-scope-virtualbox/resolute,resolute 0.1+13.10.20130723-0ubuntu4 all
  VirtualBox scope for Unity

virtualbox/resolute 7.2.6-dfsg-4 amd64
  x86 virtualization solution - base binaries

virtualbox-dkms/resolute 7.2.6-dfsg-4 amd64
  x86 virtualization solution - kernel module sources for dkms

virtualbox-ext-pack/resolute,resolute 7.2.6-1 all
  extra capabilities for VirtualBox, downloader.

virtualbox-guest-additions-iso/resolute,resolute 7.2.6-1 all
  guest additions iso image for VirtualBox

virtualbox-guest-utils/resolute 7.2.6-dfsg-4 amd64
  x86 virtualization solution - non-X11 guest utilities

virtualbox-guest-utils-hwe/resolute 7.2.6-dfsg-4 amd64
  transitional package for virtualbox-guest-utils

virtualbox-guest-x11/resolute 7.2.6-dfsg-4 amd64
  x86 virtualization solution - X11 guest utilities

virtualbox-guest-x11-hwe/resolute 7.2.6-dfsg-4 amd64
  transitional package for virtualbox-guest-x11

virtualbox-qt/resolute 7.2.6-dfsg-4 amd64
  x86 virtualization solution - Qt based user interface

virtualbox-source/resolute 7.2.6-dfsg-4 amd64
  x86 virtualization solution - kernel module source
4

So no ISO for Lubuntu 26.04 LTS was used?
Would it be a great problem to download it and do a fresh install?

5

Indeed, this was an upgrade.

And unfortunately it will be a long time before I am able to do a fresh install and migrate.

If I have no choice, I will remain with the UI quirks of lightdm for a longer time.

6

Is this a missing window list on the bar at the bottom of the virtualbox window? Is this what you are looking for?

7

I don’t actually remember, which package(s) can be installed inside the guest. DKMS looks like a promising start and X11.

You may also want to consider a more native solution, like virt-manager, which can setup QEMU/KVM VM’s. It has rendered VirtualBox obsolete for me; the latter is only available in ‘multiverse’, so no official support whatsoever in Ubuntu.

8

@Actionparsnip It’s the whole panel that’s missing. The “Start” button, app list, tray, clock, everything.

@peterwhite23 I may just do some trial and error with those packages, maybe I get lucky.

Regarding virt-manager, there was a time many years ago when I might have done that even if there had not been any issue, just to learn about a new technology. :joy: :joy::joy: Those were times when I was spending quite a bit of time on the old ubuntuforums, supporting people who were asking all kinds of questions, as you are doing now. Alas, those times are gone. :worried:

The issue is not so bad for such a drastic move. It’s unpleasant, but as long as lightdm kind of works, it’s enough for me. I rarely use that VM via UI.

I would prefer to find a proper solution. But if not, I will just leave it as it is, with lightdm.

Does anyone know, has there been a switch from X11 to Wayland in Lubuntu between 24.04 (I managed to find this is what I had before the upgrade) and 26.04? Could that be a reason?

9

Maybe it doesn’t have to be an actual drastic move. Do it right and you might just be able to reuse/migrate the VB image. But I don’t want to try and sell you anything.

10

You can reset it with
http://askubuntu.com/questions/64631/ddg#64664
Sets it back to defaults and you can configure from there

11

I had tried one of the methods where I delete the file to reset the config, although I seem to be too old to remember the details (even though it was only like a week ago, geez!) . But it didn’t solve it.

It doesn’t seem to be an issue with the content of the panel, but a deeper display problem, which prevents it from being created at all.

I suspect something around video drivers and X11/wayland compatibility, but I wouldn’t know where to take it from there. I was hoping maybe someone had the same issue I had and found a solution.

I still have to try going through apt packages and see if that helps. I just wasn’t able to get to that today.

12

I have Lubuntu running in Virt-Manager (KVM/QEMU) very successfully and it does not show the problem that you are seeing using Virtualbox.

screen
screen1920×1080 103 KB

Apart from the lack of screen icons which I hate, preferring launchers in a second panel on the left edge of the screen (still to figure out if that’s even possible in Lubuntu) but as you can see the one bottom panel is as I want it, not transparent.

13

I’m not sure that installing a new OS and hypervisor is a proper solution to a guest taskbar issue, even if virt-manager is actually better than VB.

14

@louis_nichols did you try to change the graphics controller in VB or connect to the VM via RDP (or VNC)?

15

@ajgreeny Unfortunately, I truly don’t have the available time to consider that migration. I did look into virt-manager and, as I learned it is Linux only, I realized that I missed to mention at any point that the host in this case is a Windows server. So virt-manager not an option. My bad. There are alternatives to Virtualbox under Windows also, but a migration is beyond my reach right now.

@iamthomasremy Yes, actually. I had forgotten. There are three options there (I don’t have the machine in front of me right now, and I don’t remember their names). I tried one additional one from the default. Virtualbox complained that it is an old interface and not recommended but allowed me to use it. But the issue was still present. As I was wondering if there was a point in trying the third one, I got distracted and then forgot about it. Think there’s a chance it works?

In the meantime, I managed to de-uglify the desktop under lightdm a bit, and it is now fairly usable. I don’t care that much about the aesthetics, so I can probably live with that.

I’m just wondering if someone from the team would be interested in treating this as a bug to look into. I’m not picky about sddm VS lightdm but it might matter to others. If there’s a bug in sddm, I think that is used also by Kubuntu, right? So the bug might pop up for more people soon.

1 Like
16

PS: in the meantime I also tried the apt package virtualbox-guest-x11 from the repo but it also didn’t solve it.

1 Like
17

Actually you did mention it at the beginning :sweat_smile:

I don’t think so, I believe the issue here is with the OS, not with the hypervisor. I was just looking for ideas of some easy config changes to try when I talked about that setting in VB. Sorry :sweat_smile:

@louis_nichols I read that you don’t remember what was the version before the update, do you remember at least if it was an LTS or you have no idea? I wanna try to boot a VM in VB and try to upgrade it to 26.04.

18

I found out in the meantime. I went from 24.04 to 26.04. I think 24.04 was also LTS, iirc.

I think these are both under X11 right?

1 Like
19

I know that with Ubuntu 26.04 (no flavor) now using GNOME 50, you can’t use X11 as the support has been dropped by GNOME.

From what I’m reading about LXQT, I feel like both (X11 and Wayland) should be possible. Idk what’s the default tho.

20

@louis_nichols so, I installed 24.04 and did the upgrade to 26.04 inside VB 7.2.8. As you can see in the screenshot below, the taskbar still appears correctly after the upgrade.

image
image1410×1011 191 KB

Maybe there was a package in your install that broke something?