If you’re using
netctl to manage your network connections on Arch and need to connect to a hidden wireless network, make sure that you have
Hidden=yes in your config file e.g.
Description=Your Description Interface=wlp6s0 Connection=wireless IP=dhcp Priority=10 Security=wpa ESSID="<SSID Name>" Key="<PASSPHRASE>" Hidden=yes
netctl will refuse to connect without
Hidden=yes, even if all of the other options are correct.