Same here. Already tried these instructions wich are updating:
sudo pacman-mirrors -f3
sudo pacman -Syyu
Then startx that says:
Couldn't exec startkde: No such file or directory.
I have no: ~/.local/share/plasma/plasmoids/
There is /usr/share/plasma/plasmoids/
But no org.kde.plasma.eventcalendar in there.
Should I delete org.kde.plasma.eventcalendar or should I try this chroot thing ?