24.04 Kubuntu Wayland stuck on login screen

Ubuntu Version: 24.04 (lsb_release -a: 24.04.3)

Desktop Environment: KDE Plasma

Problem Description:

If I choose Plasma (Wayland) on the login screen (paraphrased, I do not remember the exact label), once I type in my password, the system freezes on that login screen. I cannot switch back to a TTY; however I can log in from another computer over SSH & poke around.

24.04 + KDE Plasma + Wayland had been working great for me for a year, this problem has only appeared just this week; see timeline further down.

The problem does not happen if I choose Plasma (X11): I type in my password, then the splash screen shows up, then my desktop session starts.

Relevant System Information:

This is a Dell Precision 7550 laptop with an NVIDIA card; per lspci:

01:00.0 VGA compatible controller: NVIDIA Corporation TU117GLM [Quadro T1000 Mobile] (rev a1)

(On the X11 session) Software & Updates > Additional Drivers says Using X.Org X server -- Nouveau display driver from xserver-xorg-video-nouveau (open source).

Timeline:

  • 2021-11: system installation; 20.04/GNOME/X11
  • 2023-09: upgrade to 22.04; still GNOME/X11
  • 2025-01: upgrade to 24.04; migration to KDE/Wayland
  • 2025-*: 24.04/KDE/Wayland works great
  • 2026-01-28: last successful boot & login on Wayland
  • 2026-02-02: upgrade & reboot; Wayland can no longer get past the login screen

Screenshots or Error Messages:

I’m uploading sudo journalctl -b… for:

Working backward from plasma-ksplash.service: start operation timed out. Terminating., I feel like the most salient difference comes from the kernel nouveau messages; specifically:

  • On 2026-01-28:
Jan 28 07:47:45 legouguec-Precision-7550 kernel: [drm] Initialized nouveau 1.4.0 20120801 for 0000:01:00.0 on minor 2
Jan 28 07:47:45 legouguec-Precision-7550 kernel: nouveau 0000:01:00.0: [drm] Cannot find any crtc or sizes
  • On 2026-02-03:
Feb 03 07:31:55 legouguec-Precision-7550 kernel: [drm] Initialized nouveau 1.4.0 20120801 for 0000:01:00.0 on minor 2
Feb 03 07:31:55 legouguec-Precision-7550 kernel: nouveau 0000:01:00.0: [drm] fb0: nouveaudrmfb frame buffer device

On the one hand the message during the “working boot” sounds somewhat negative (“Cannot find any blah”), on the other hand, perhaps this new nouveaudrmfb frame buffer device is problematic & should be inhibited?

What I’ve Tried:

Honestly, for now, not much. Searching for combinations of kde plasma 5.27 wayland login stuck hang ksplash nouveau yields a lot of matches spanning a lot of distros; since

  • the system was stable until that 2026-02-02 reboot,
  • this is my daily driver for $DAYJOB,
  • X11 works as a crutch for now,
  • there’s the 26.04 Hail Mary on the distant horizon,

I feel a bit conservative about applying the advice I’ve found (apt install --reinstall foo bar, switch to proprietary video drivers, tinker with /etc/environment).


First-time poster, hope this was in good form, apologies if not!

I guess problem with new Mesa 25.2.8 drivers. These were released around 27.1. 2025. You can try newer kisak PPA Mesa temporarily until it is fixed in Kubuntu.

I guess problem with new Mesa 25.2.8 drivers. These were released around 27.1. [2026]

Mm, yeah, reviewing history.log, the apt full-upgrade --autoremove --purge on 2026-02-02 morning (before rebooting & observing the issue) brought the mesa bump from 25.0.7 to 25.2.8 from LP#2126037.

You can try newer kisak PPA Mesa temporarily until it is fixed in Kubuntu.

Good to know that’s an option. Wondering if I should report this to Kubuntu Forums or Launchpad’s mesa tracker… might just watch these spaces & soldier on with X11 for now?

At any rate, thanks for the pointers!

Hello! I got exactly the same problem and in my case it was indeed caused by the Mesa drivers. I’ve managed to downgrade them via the 2 following commands:

$ sudo apt install 'libgbm1'='24.0.5-1ubuntu1' 'libglapi-mesa'='24.0.5-1ubuntu1' 'libegl-mesa0'='24.0.5-1ubuntu1' 'libgl1-mesa-dri'='24.0.5-1ubuntu1' 'libglx-mesa0'='24.0.5-1ubuntu1' 'mesa-va-drivers'='24.0.5-1ubuntu1' 'mesa-vdpau-drivers'='24.0.5-1ubuntu1' 'mesa-vulkan-drivers'='24.0.5-1ubuntu1'
$ sudo apt remove mesa-libgallium

Also you can pause any updates for them like this:

$ sudo apt-mark hold "libgbm1" "libglapi-mesa" "libegl-mesa0" "libgl1-mesa-dri" "libglx-mesa0" "mesa-va-drivers" "mesa-vdpau-drivers" "mesa-vulkan-drivers"