I've had Arch stable, with XFCE, lightdm and xorg, working fine for over a month.

In the last day though, when I login through lightdm-gtk-greeter as usual, XFCE launches but I only get partial functionality. The toolbar at the top shows and I can launch all my programs, but the space where the desktop should be is completely black with none of my folders/programs and right clicking on it does nothing. My programs launch over top of the black, but with more than one program open, I can only interact (type or click) with one at a time. I can't choose what program is on top. I can't Alt Tab either, nor switch workspace.

Also there are just a few utilities that won't launch: nvidia X-server settings ; Window Manager ; Window Manager Tweaks .

I have the nvidia package installed - I'm using a GTX1070. I'm on the "linux" kernel. I have also tried linux-lts instead with nvidia-lts but I get the same behaviour.

When I Ctrl Alt F2 out of XFCE, login and run startx, there is a black screen for 2 seconds then it just exits back to terminal. Usually it doesn't show any errors but sometimes there is a keyboard error (about exceeding 255 keycode in X11) and an error (could not resolve keysym XF86 MonBrightnessCycle).

In var/log/Xorg.1.log , there were a few errors at some point: failed to load modules nouveau, nv and fbdev as they "don't exist" ; open /dev/dri/card0 no such file or dir ; Screen 0 deleted because of no matching config session. That's all.

In the lightdm log there was a warning about Error getting user list from org.freedesktop.displaymanager.

In one of tbe logs I checked yesterday there was something about "twm command not recognised" or similar. I don't remember what log it was. Possibly something in journalctl or lightdm.

My .xinitrc is in ~ as it should be. It was copied from /etc/X11/xinit and to the end I added "exec startxfce4" .

Last thing to note is my ~ is encrypted with ecryptfs (always has been and always worked).

Sometimes when I login through lightdm-gtk-greeter (correct password) it just shows a black screen then sends me back to the greeter promptly.

Once in about 100 tries XFCE seemed to work fine for some reason, but on a restart it started failing again.


Any help would be greatly appreciated.

Edit: I have run pacman -Syu , everything is up to date.

When X is running can you open a terminal and run;

I think XFCE uses its own window manager. I wonder if you have some race condition where twm is getting started, or worse you have two window managers running (I don't know if that is even possible)?

Did you recently install any updates? If so, what were they?

I will try that asap , but for now I have a new problem. I boot into "linux" or "linux-lts" and on both lightdm-gtk-greeter starts but now keyboard and mouse inputs don't work, like it's frozen. I can't get into a tty either because Ctrl Alt F1/2/etc do nothing.

Can I disable lightdm in GRUB or do I need to disable it from say an Arch installTion .iso disk?



Well I run pacman updates regularly so yes, but I don't know what they all were. Once I can boot again I'll find out.

I suggest getting a live image (like Knoppix or something similar) and boot to that using a USB stick. The Arch install iso requires manual configuration of everything, so it is painful to use it as a rescue disk. Once booted in a live USB image, you can chroot over to your hard drive to edit grub to boot into text mode:

https://askubuntu.com/questions/1637...s-in-text-mode

The above is written for Ubuntu, but should work the same in Arch. You can then boot to text mode and try manually starting X from the command line to look for errors. You might also try the Arch forums to see if anyone experienced anything similar. Arch users are generally very knowledgeable.

Unfortunately, I'm not an Arch user, although I used Arch briefly myself on my laptop. It broke in less than a week of keeping things updated daily with pacman. That is when I went back to Debian, which is what I have used daily for about 15 years. Arch is a cool concept, great learning tool, and has probably the most technically experienced user base of any distribution. The problem with keeping everything bleeding edge is that it breaks.

Ok I'll give that a go. I've found in the past the Arch install .iso works fine (no configuration needed). But I erased the .iso so I might try your idea instead.

I like Debian also. Before switching to Arch I used it for a year or so. But I wanted more up to date software, particularly nvidia. I will persevere with Arch for now.

I'll try Arch forums if needed

(I'm not an Arch user either, nor XFCE, nor LightDM. Nevertheless, problems OP describes are generic in nature, not specific to any of those three.)
Most of what you describe sounds like could result from mismatch between the proprietary (non-FOSS) video driver version and the installed kernel(s). Generally, new kernel installation requires follow-up NVidia driver installation to match. Sorting through the described trouble may be easier by starting with uninstallation of the NVidia driver precisely and completely according to the instructions for them provided with the installation package used to install it. It can be installed again after ensuring everything works normally without it.

At the Grub screen following POST, enter edit mode (with most distros the E key) and append a 3 to the line that begins with linu (which may wrap onto the next line. This should leave you with a login prompt when init completes, from which you can perform repairs.

If Plymouth is installed, it could cause trouble like this. It can be bypassed using same method as for bypassing LightDM, by appending plymouth.enable=0 or noplymouth.

Exactly why did you create .xinitrc, and why did you add exec startxfce4 to it? If simply startx doesn't produce an XFCE session on an otherwise OK system, then try 'startx /usr/bin/startxfce4' instead.

Failing to load modules that don't exist are normal messages. Still, when X is the problem, pastebinning Xorg.#.log should accompany any help request.

I chickened out and just reinstalled Arch. It's fine now

Thanks for the help though

Check your pacman log regularly after each -Syu or at least scroll back if not huge update and look for changes or things that need to be addressed like *.pacnew and/or *.pacsave files etc,,,. Normally packages that get replaced don't cause problems (ime) but always watch what pacman is doing. Xfce updated at least once this year and did some rearranging on this pc, not like what you described but significant changes did happen, on a plus side it actually corrected a minor issue after 2yrs...

Thanks I'll keep it in mind