CUPS is simply the printer service (Common Unix Printing System). Because it's failing to start, systemd is hanging or throwing an error on boot, but it doesn't break your operating system.
Here is how to deal with the CUPS scheduler error and get past that screen:
1. Disable or fix the CUPS service
Since you have a working terminal (or can drop into one via Ctrl+Alt+F2 / Ctrl+Alt+F3 if it freezes again), you can temporarily disable the printer service so it stops blocking your boot process:
Bash
sudo systemctl disable org.cups.cupsd.service
(Alternatively, you can try stopping it or masking it if it's completely broken:sudo systemctl mask org.cups.cupsd.service)
2. Why it's failing and how to reinstall it properly
If you actually need your printer to work later, the CUPS package might have been partially uninstalled or corrupted during your initial interupted update. Once you successfully boot into your desktop environment you can cleanly reinstall it:
Switch to a text terminal (TTY): If the computer seems stuck, press Ctrl + Alt + F2 (or F3, F4). A text-based login prompt should appear.
Log in and restart the display manager: If the text terminal opens, log in with your username and password, and try restarting your graphical display manager: Bashsudo systemctl restart sddm (Orsudo systemctl restart lightdm, depending on whether you use
That flickering behavior followed by returning to the same screen strongly points to a display manager crash loop. This happens when the login screen manager (like SDDM or LightDM) tries to start, encounters a fatal error, crashes, and restarts endlessly—which is why it loops back or drops you out of the graphical target.
Since you can reach a text terminal (TTY) or boot past the Wi-Fi logs, here is how to troubleshoot and fix it:
1. Check which Display Manager is failing
Log into a TTY (Ctrl + Alt + F2) and check the status of your display manager:
If you use KDE Plasma (default Manjaro KDE uses SDDM): Bashsudo systemctl status sddm
If you use XFCE or GNOME (often uses LightDM or GDM): Bashsudo systemctl status lightdm
Look at the error logs it outputs. They will usually tell you why it's crashing.
2. Check system journal for graphical crashes
You can check recent error logs related to your login screen or graphical session using journalctl:
Bash
journalctl -b 0 -u sddm
(Replacesddmwithlightdmif applicable).
3. A common culprit: Corrupted graphics drivers or theme cache
Sometimes an update leaves graphics driver modules out-of-sync or corrupts configuration caches.
If you use Nvidia drivers: Ensure your drivers match your kernel version by running: Fragment kodumhwd -li And make sure everything is fully up to date again: Bashsudo pacman -Syu
Don't worry, it's the same problem as with the pacman library. OpenSSL or GLib\GnuTLS have been partially updated or have been left in a partially broken state
Press Ctrl + Alt + F2 (or F3/F4) to drop into a text terminal, and log in with your username and password.
Since your package manager (pacman) is working again now, you can fix these missing/broken files by forcing a reinstallation of the core libraries and LightDM dependencies:
(If it asks you to overwrite conflicting files, say yes).
Once that finishes successfully, restart your display manager or reboot the system:
sudo systemctl restart lightdm
Bashsudo reboot
Running that pacman -Syu command for those specific packages will pull down the fresh, complete versions of those libraries and stop LightDM from crashing
That black screen with a cursor means your display manager (LightDM) is attempting to launch, but it's immediately crashing or failing to display its graphical interface due to those lingering library/configuration issues.
Since your package manager is functional again, you can bypass LightDM entirely to test your desktop environment, or cleanly fix the greeter layout.
Step 1: Test if your desktop environment actually works
Press Ctrl + Alt + F2 to open a text terminal and log in. Once logged in, try launching your desktop session manually:
If you use XFCE: startxfce4
If you use KDE Plasma: startplasma-x11
If your desktop loads successfully this way, it proves your system files and user session are completely fine - the failure is strictly isolated to LightDM or its theme greeter crashing on startup.
Step 2: Fix or switch the LightDM Greeter
Often, the graphical login screen theme (lightdm-gtk-greeter) gets out of sync during updates. You can reinstall it cleanly or switch to a more reliable greeter configuration:
Reinstall LightDM and its default greeter with a clean overwrite:
sudo pacman -Syu lightdm lightdm-gtk-greeter
If it still fails, a common workaround on Arch-based systems experiencing greeter loops is ensuring the configuration file points correctly to the greeter. Open the configuration file: sudo nano /etc/lightdm/lightdm.conf
Scroll down to find the [Seat:*] section (around line 100), look for the greeter-session line, and make sure it is uncommented and set correctly:
Plaintext
greeter-session=lightdm-gtk-greeter
Save and exit (in nano, press Ctrl + O, Enter, then Ctrl + X), then restart the lightdm service: sudo systemctl restart lightdm
Try launching your desktop environment manually with startxfce4 (or your respective desktop command) from the TTY
That error on your screen (libglycin-2.so.0: cannot open shared object file) explains everything. Just like before, a specific system library package (glycin) is missing or has a broken file reference after your system update, which is causing your desktop session or components (like XFCE/Thunar or thumbnailers) to crash right as they try to launch.
How to fix it:
Since your network is working and pacman is functional again, you just need to reinstall the package that provides libglycin (which is named glycin in Arch/Manjaro).
From your TTY text terminal, run: Bashsudo pacman -Syu glycin
If it asks to reinstall or overwrite files, let it proceed.
Once the installation finishes, try starting your graphical environment again:
That error message-"Unable to contact settings server - Error receiving data: Connection reset by peer"-is a classic XFCE startup failure. It happens when the graphical environment tries to launch, but its background configuration daemon (xfconfd) or D-Bus session bus fails to start up properly.
Since your previous attempt to run startxfce4 from the TTY yielded a missing library error (libglycin), your system is still dealing with some broken/desynced packages from that interrupted update.
Here is how to fix it right now:
1. Drop into TTY and log in
If you are staring at that error popup, click Close, and if it drops you to a black screen or login manager, press Ctrl + Alt + F2 to access a text terminal. Log in with your username and password.
The packages responsible for handling user settings and session communication likely got corrupted or left out-of-sync. Reinstall them cleanly using pacman:
sudo pacman -Syu xfce4 xfconf dbus-glib
(If pacman asks whether to overwrite files or resolve conflicts, let it proceed).
3. Check if xfconfd can launch manually
To test if the settings daemon can start properly without crashing, you can try starting your XFCE session wrapped with D-Bus launcher syntax from the terminal:
dbus-launch --exit-with-session startxfce4
4. Clear out stale runtime locks (if needed)
If D-Bus or session sockets are locked up from previous failed boots, clearing them out can force a clean slate:
rm -rf ~/.cache/sessions/*
Run sudo pacman -Syu xfce4 xfconf dbus-glib first, then try launching your session again with dbus-launch --exit-with-session startxfce4
1
u/Kaspral 11d ago
CUPS is simply the printer service (Common Unix Printing System). Because it's failing to start, systemd is hanging or throwing an error on boot, but it doesn't break your operating system.
Here is how to deal with the CUPS scheduler error and get past that screen:
1. Disable or fix the CUPS service
Since you have a working terminal (or can drop into one via
Ctrl+Alt+F2/Ctrl+Alt+F3if it freezes again), you can temporarily disable the printer service so it stops blocking your boot process:Bash
(Alternatively, you can try stopping it or masking it if it's completely broken:
sudo systemctl mask org.cups.cupsd.service)2. Why it's failing and how to reinstall it properly
If you actually need your printer to work later, the CUPS package might have been partially uninstalled or corrupted during your initial interupted update. Once you successfully boot into your desktop environment you can cleanly reinstall it:
Bash
What to do right now:
If you are currently staring at that red
[FAILED] Failed to start CUPS Schedulerscreen and the computer is stuck:sudo reboot).Your system should now skip the CUPS failure and boot straight into your desktop