It means I followed the instructions here: Failed to start D-Bus after system update
Basically, I re-installed D-bus using the “dbus-daemon-units” package instead of the default dbus-broker one.
I solved the issue with Wifi (writing this in my Manjaro installation now) by reinstalling all packages mentioned by the output in the “pacman -Qkk” command with the “–overwrite ‘*’” flag. Re-running “pacman -Qkk” chrooted in the live USB didn’t then give those errors. However, running the same command booted into Manjaro does return the same errors (even though Wifi works). Is that anything to be worried about?