… this one too?
sudo rm -fr /etc/pacman.d/gnupg
sudo pacman-key --init
sudo pacman-key --populate archlinux manjaro
sudo pacman-key --refresh-keys
refresh your list of mirrors
for example:
sudo pacman-mirrors -c Germany
sudo pacman -Syyu
if it fails again (it probably will), do the first set of commands
info sourced from here:
Getting invalid or corrupted package (PGP signature) error when updating - #4 by Nachlese
look at this and the links within it before you go ahead and copy/paste commands