I’m a proud Logitech-user and have always been a loyal costumer towards Logitech. Since I’m using both MS Windows (for those tiny moments I ever find time to play a game) and Linux , I did setup my link between the keyboard and wireless sender to be encrypted. (aka secure mode.). This works perfectly in Linux too, until the day you figure out you for some reason would like to resync your wireless keyboard in linux. Since reseting wireless receiver (holding in reset button for 10 seconds) resets the private key on the sender, and not the keyboard – I was stuck without a keyboard as my keyboard always tried to send the encrypted handshake for syncing. When this happens in windows, SetPoint will detect this and you will be able to redo the normal resync procedures when you setup secure mode.
Anyway, quick fix for this is to:
a) Press Ctrl + Alt + F12.
b) Press connect button on the receiver.
c) Press connect button on the keyboard.
d) Press the escape key.