Wi-Fi networks not listed

First start

The initial scan may take a couple of minutes, first be patient before assuming it's an issue

Check if network-manager is installed:

dpkg -s network-manager

if the response is the following:

dpkg-query: the package 'network-manager' is not installed

go to wpa_supplicant

if the response is the following:

Package: network-manager
Status: install ok installed

this line may appear in KlipperScreen.log:

Log

[wifi_nm.py:rescan()] [...] NetworkManager.wifi.scan request failed: not authorized

if version of KlipperScreen installed was previous than v0.3.9, then re-run the installer and reboot

Alternative

in order to fix this polkit needs to be configured or disabled:

here is how to disable polkit for network-manager:

mkdir -p /etc/NetworkManager/conf.d
sudo nano /etc/NetworkManager/conf.d/any-user.conf

in the editor paste this:

[main]
auth-polkit=false

Then restart the service (or reboot):

systemctl restart NetworkManager.service
systemctl restart KlipperScreen.service