Ubuntu MATE 23.04 Testing

A new release of Ubuntu is on the horizon! And so is the release of Ubuntu MATE 23.04 (Lunar Lobster)! :new_moon: :lobster:

Thank you to everyone who has helped with previous testing, including the initial ISOs.
We can't say enough how important the community contributions are during these testing periods. :raised_hands:

Testing for Ubuntu MATE 23.04 is underway. This testing is focused on the Beta and daily releases. Final release is scheduled for April 20. 23.04 is an interim release, and will be supported until January 2024.

If you've been nervous about testing, now is a great time to ask for help and join in! Chat with other testers on IRC (#ubuntu-quality on Libera Chat) or Telegram (Ubuntu Testers). Testing doesn't require any coding knowledge, can take as little as 30 minutes to complete a test case and file a report, and can be done on a VM or bare metal with a spare machine. :blue_book:

Directions and helpful hints are below.

Lunar Lobster Release Notes

Ubuntu MATE chat on Wimpy's World

You can find the test ISO here :floppy_disk: :

You can test on either a spare machine or a virtual machine, and please let us know in this thread if you encounter any problems, and please file Bug reports. The sooner the team know about a problem, the sooner they can tackle it! :clock11:

If you’re new to ISO testing, or need a refresher, here’s a quick guide:

First of all, you’ll need a Launchpad/Ubuntu One login. Go here to create one if you haven’t done so already.

You’ll want to download the Lunar Lobster daily build here: Ubuntu MATE 23.04 (Lunar Lobster) Daily Build

Take a look at the testsuites for Ubuntu MATE, many of which take less than 30 minutes to complete. :clock1030:

Follow the directions in the testsuite. If it does all of those things, great! If it doesn’t, however, we need your help. Click on the link at the top of the page that reads “Report a bug against the contents of this testcase.” Sign in with your Launchpad/Ubuntu One account.

Follow the directions in the bug report, and be as specific as you can! This is a key step - an unreported bug will be an unfixed bug. :bug: :receipt:

While the Ubuntu MATE 23.04 Release Notes are not available at this time, we will update this page once they are online.

There have been several updates to Ubuntu MATE packages for release in 23.04 as well as the underlying Ubuntu base packages. There are some [major changes} coming in this release, including:

  • PipeWire replaces PulseAudio
  • Flatpak removed from default install

Early testing and bug reporting will help improve the final release.

Thank you again for testing and for reporting your issues, concerns, observations, and questions in this thread! :green_heart:

You can upgrade to the developmental release using the instructions below. However we encourage testers to try the daily ISOs as much as possible. We recommend anyone who upgrades their system to the developmental version to backup first! :harddrive: If you rely on your system as your daily driver, it might be advisable to wait for the final release.

:stop_sign: Friendly reminder that developmental releases HAVE the possibility of breaking and requiring a reinstall. So please keep that in :brain: should you choose to run it as your daily driver. :stop_sign:

To upgrade, press Alt + F2, and type:

update-manager -cd

If you aren't prompted to upgrade, press Alt + F2 again, then


and click Settings and Livepatch. Go to the Updates tab and toggle the option for 'Notify me of a new >Ubuntu version' to 'For any new version.'

Press Alt + F2 again, and then type:

update-manager -cd

Please be aware of the following bug with caja and the menu.

Please mark as affects you if you encounter this.


Just upgrade to this after encountered issues on another upgrade from 20.04 to 21.10

This operating sistem is not usable (Desktop - file access through Caja). So do not upgrade to it...

Leave the developer to play... is for them not for users... there is nothing to be tested here

  • for now I wait for caja fix (this is a netbook rarely used)
  • touchpad pointer sometimes stack after login (after upgrade to 21.10) look that is fixed back... need more test
  • desktop loading stuck one minute waitung for something, not fixed (issue after upgrading to 21.10)

I am not a developer, so do not want to waste any more time with this stafs...
most of upgrades I run in some isues that continue to exist couple of years after... so the lesson is let keep sistem outdated... what i have now working ok on 20.04 will remain there

It still has snaps I suppose. when will they be removed? Do we have to wait like it was with unity?

Ubuntu Mate flavour has nothing to do with Snaps... so you pointed it wrong here

There is a huge difference between mate desktop and ubuntu mate regarding snaps.
Mate desktop is possibly snap free.
ubuntu mate as it is delivers mate welcome trough snaps and also firefox,so is not as snap free as you might suppose.

This is a reminder to please conduct yourselves civilly.


Issues with this bug have been resolved.

Thanks @ArrayBolt3 :green_heart:

The team would encourage everyone to keep testing.


Fresh install in VM yesterday with no errors. Caja issue is now a non issue.
Tempted to do an upgrade on my host machine running 22.10 Kinetic.


is it normal that openbox is installed by default? and what is its use? I tried a little to touch these parameters and nothing changes :thinking:


Openbox is installed for some reason. So, Openbox config tool is used to configure Openbox session. Try choosing it in your login window instead of MATE session and check changes.
It may be related to Arctica Greeter development, because it is mentioned in greeter config files as a fallback session (e.g. /etc/lightdm/lightdm.conf.d/90-arctica-greeter.conf).


Call for testing: changes in fonts-ubuntu package. No need to install .deb file manually, just update and upgrade your system.


I have filed 3 bugs that ultimately culminated in crashes:

Other than that though, I've had a good time testing 23.04. I'm finishing my usual yearly X.04 review as I am trying to post it sooner rather than later my friends :slightly_smiling_face:


Upgraded today from 22.10 (kinetic) to 23.04 (lunar) without a hitch so far.


Upgraded today from 22.10 (kinetic) to 23.04 (lunar) without a hitch.... except that

  1. The menu "Software update" and "System & updates" are not responding.
  2. My weather indicator has lost... its weather.
  3. Language option button in the panel just disappeared. I try to open "Language support" and the window opens and close within a second..... and then the language choice reappeared.... weird.

re Update manager
If I do: sudo apt-get upgrade
I get this
E: Malformed entry 1 in list file /etc/apt/sources.list.d/rvm-ubuntu-smplayer-hirsute.list (Component)
E: The list of sources could not be read.

How do I get out if this ? I didn't know anything about smplayer in the first place.....

Will come back if I find something else


1 Like

The directory /etc/apt/sources.list.d/ is empty on new installs; so the file within it titled rvm-ubuntu-smplayer-hirsute.list was added by a user on your system with sudo privileges.

I'd expect that source to be disabled on release-upgrade, thus I'd not expect an issue with it, however the contents of it are now invalid, with the error found on line 1 (malformed entry 1). You'll need to correct that line, or for us to help with it, provide the contents.

I'd expect line 1 to contain a URL that I'd open in a web browser to check the site support lunar or 23.04, as some sites add support after release & thus it maybe you've release-upgraded too early for them to provide support; it's a 3rd party source thus your responsibility to manage on your system.

Sorry you'll have to wait for someone else to advise on your earlier issues.


Since I don't use smplayer what is the way to get rid of these lines ?
I went to etc/apt and line 1 reads:
deb-src http://ppa.launchpad.net/rvm/smplayer/ubuntu/main # disabled on upgrade to impish disabled on upgrade to lunar

1 Like

I'd use a text editor (vim specifically) and just comment out the entry; ie. add a "#" to the start of the line, and its treated as a comment & ignored. This maybe not your best option (esp. use of the editor I'd use (vi) as that usually seen as scary (and impossible to get out of I gather)).

I'll provide a link to Repositories/Ubuntu - Community Help Wiki

ie. open Software Sources and go to the Other Software tab, and you should see it I hope. There is a checkbox with a tick in it; just remove that tick and the system will add the "#" in the file I mentioned for you.

FYI: If you open the URL in your last comment, you can use your web browser to view what release it supports... You'll note lunar or 23.04 is not listed... (navigate to Index of /rvm/smplayer/ubuntu/dists this page for a list of what is supported)


As I said earlier on, if I try to open "Software & Updates"... I get no response.

1 Like