Uknown error on shutdown

[Wollie]

I would try one of the solutions shown here:

No irq handler for vector / Failed to start Load/Save Screen Backlight Brightness of backlight:acpi_video0

This solved the issue for me, no more errors and it boots normally into manjaro. You can just copy the whole string in a tty. To enter a tty just press ctrl+alt+f3 when the error appears at boot sudo sed "s/\(GRUB_CMDLINE_LINUX=\)\"\"/\1\"acpi_osi=Linux acpi_backlight=vendor\"/" /etc/default/grub -i after that sudo update-grub then just reboot and everything should be fine. hope this will help you

Sometimes I boot up to a blank screen. Sometimes it works just fine

Found a solution in a thread titled “[SOLVED] Gnome (GDM) wont auto start on boot” in an archlinux.org forum: Solution was to Unlink /etc/systemd/system/display-manager.service and the again enabling gdm service with systemctl enable gdm.service.