Login screen does not appear after upgrade to 23.04

[meladoro]

Upgraded today to Kubuntu 23.04 from 22.10, simply using the prompt that popped up in the bottom right of the screen (warning me that 22.10 would reach EOL in less than 90 days).

All seemed to go well, but upon rebooting the system to complete installation, I couldn't seem to continue booting past the manufacturer's screen (which in my case, prompts me to unlock my fully encrypted drive).

I turned out to be able to get a TTY, logged in and tried to start X manually by running `startplasma-x11`. This failed with the following error:

meladoro@localhost:~$ startplasma-x11
$DISPLAY is not set or cannot connect to the X server.

Trying `startx` also fails:

meladoro@localhost:~$ startx
X.Org X Server 1.21.1.7
X Protocol Version 11, Revision 0
Current Operating System: Linux localhost 6.2.0-20-generic #20-Ubuntu SMP PREEMPT_DYNAMIC Thu Apr 6 07:48:48 UTC 2023 x86_64
Kernel command line: BOOT_IMAGE=/vmlinuz-6.2.0-20-generic root=/dev/mapper/vgkubuntu-root ro quiet splash vt.handoff=7
xorg-server 2:21.1.7-1ubuntu3 (For technical support please see http://www.ubuntu.com/support)
Current version of pixman: 0.42.2
Before reporting problems, check http://wiki.x.org
to make sure that you have the latest version.
Markers: (--) probed, (**) from config file, (==) default setting,
(++) from command line, (!!) notice, (II) informational,
(WW) warning, (EE) error, (NI) not implemented, (??) unknown.
(==) Log file: "/var/log/Xorg.0.log", Time: Tue Apr 25 10:31:16 2023
(==) Using system config directory "/usr/share/X11/xorg.conf.d"
(EE)
Fatal server error:
(EE) no screens found(EE)
(EE)
Please consult the The X.Org Foundation support
at http://wiki.x.org
for help.
(EE) Please also check the log file at "/var/log/Xorg.0.log" for additional information.
(EE)
(EE) Server terminated with error (1). Closing log file.

Finally, trying `startplasma-wayland` sort of worked, in the sense it got me to a graphical environment.

Of course, this is not suitable, as I understand that the Wayland session is there for testing purposes only, and not actually supported. I would like to restore the normal login behavior, with a graphical login screen that starts a Xorg session by default.

Any ideas or pointers are welcome. Thank you very much.

[Schwarzer Kater]

Specifications of your hardware (CPU, GPU, etc. …)?
This could be related to the proprietary Nvidia graphics card driver, for example.

[meladoro]

Hi there, and thanks for your reply.

How do you mean? Were you thinking of anything in particular? Indeed I have an Nvidia card, but kubuntu-driver-manager indicates that the correct proprietary drivers for my hardware are installed and functioning. I'm temporarily away from keyboard, but will post lspci output, etc., very soon.

[meladoro]

Here's the output of `lspci`:

00:00.0 Host bridge: Intel Corporation 3rd Gen Core processor DRAM Controller (rev 09)
00:01.0 PCI bridge: Intel Corporation Xeon E3-1200 v2/3rd Gen Core processor PCI Express Root Port (rev 09)
00:02.0 VGA compatible controller: Intel Corporation 3rd Gen Core processor Graphics Controller (rev 09)
00:14.0 USB controller: Intel Corporation 7 Series/C210 Series Chipset Family USB xHCI Host Controller (rev 04)
00:16.0 Communication controller: Intel Corporation 7 Series/C216 Chipset Family MEI Controller #1 (rev 04)
00:1a.0 USB controller: Intel Corporation 7 Series/C216 Chipset Family USB Enhanced Host Controller #2 (rev 04)
00:1b.0 Audio device: Intel Corporation 7 Series/C216 Chipset Family High Definition Audio Controller (rev 04)
00:1c.0 PCI bridge: Intel Corporation 7 Series/C216 Chipset Family PCI Express Root Port 1 (rev c4)
00:1c.1 PCI bridge: Intel Corporation 7 Series/C210 Series Chipset Family PCI Express Root Port 2 (rev c4)
00:1c.3 PCI bridge: Intel Corporation 7 Series/C216 Chipset Family PCI Express Root Port 4 (rev c4)
00:1d.0 USB controller: Intel Corporation 7 Series/C216 Chipset Family USB Enhanced Host Controller #1 (rev 04)
00:1f.0 ISA bridge: Intel Corporation HM76 Express Chipset LPC Controller (rev 04)
00:1f.2 SATA controller: Intel Corporation 7 Series Chipset Family 6-port SATA Controller [AHCI mode] (rev 04)
00:1f.3 SMBus: Intel Corporation 7 Series/C216 Chipset Family SMBus Controller (rev 04)
01:00.0 VGA compatible controller: NVIDIA Corporation GF108M [GeForce GT 635M] (rev a1)
01:00.1 Audio device: NVIDIA Corporation GF108 High Definition Audio Controller (rev a1)
03:00.0 Network controller: Qualcomm Atheros AR9485 Wireless Network Adapter (rev 01)
04:00.0 Ethernet controller: Qualcomm Atheros AR8161 Gigabit Ethernet (rev 10)
​

[meladoro]

As you can see above, I do have an NVIDIA graphics controller (this is an Asus N56 series laptop). Browsing around, I found the following link: https://wiki.archlinux.org/title/NVIDIA/Troubleshooting—and it does have something that looks relevant to my situation (see section 1.5) but I cannot yet quite understand how to use it to troubleshoot.

Any ideas or pointers are welcome. Thank you very much.

[jlittle]

$DISPLAY is not set or cannot connect to the X server.

I'm not sure this will help, or that you're running the right command to start X11, but to get past that specific error run this first:

export DISPLAY=:0​

[meladoro]

Thank you very much for your reply. I'll be able to try your version in a little while, but it may be that I've already tried something equivalent, which I'd found in another post:

export DISPLAY=:0.0

Not sure it's actually the same, but if it is, then I guess this did not work (no effect on the relevant error messages)...

[shag00]

This may help:

[meladoro]

This may help:

Thank you! I'll be looking into this. I'm now thinking it's definitely related to NVIDIA drivers. I'll be experimenting with various drivers just to figure out what's going on, although I may end up reinstalling for unrelated reasons.

[meladoro]

I had asked this on AskUbuntu and I've now closed that question there: https://askubuntu.com/questions/1465...567775_1465692

It quite simply turns out that my old NVIDIA GPU has reached the end of the line, the 390 drivers that it was using will no longer be updated, etc. I've switched to the nouveau driver for now. In order to use the proprietary driver again, I may end up installing the current LTS Kubuntu. By its EOL, I will hopefully (and presumably) be able to move to more recent, better supported hardware. It's been a good run.

[Schwarzer Kater]

So install Kubuntu 22.04 LTS and I also suggest enabling the Kubuntu Backports PPA for newer KDE Gear etc. (and if you like you could also set the Ubuntu backports to Pin-Priority: 500 to "automatically install packages from backports" - to automatically get LibreOffice 7.4.6 for example: https://help.ubuntu.com/community/UbuntuBackports).

You should be good until 2025/2027 then.