Hi Peter, > I cannot find the error message from the service again, sorry, so I > cannot tell You, it had to do with some security parameter not set. It might be in journalctl(1)'s output. > According to the description of kernel downgrading in the wiki, I > should have downgraded linux-headers, too, but these are not in my > package cache - are they included in the kernel package now? No. It's still a package. https://www.archlinux.org/packages/core/x86_64/linux-headers/ $ pacman -Slq | egrep '^linux($|-)' linux linux-api-headers linux-atm linux-docs linux-firmware linux-headers linux-lts linux-lts-docs linux-lts-headers linux-hardened linux-hardened-docs linux-hardened-headers linux-zen linux-zen-docs linux-zen-headers linux-tools-meta $ If your cache no longer has old packages, you can use the online Archive. https://wiki.archlinux.org/index.php/Downgrading_packages#Arch_Linux_Archive -- Cheers, Ralph. https://plus.google.com/+RalphCorderoy