For some reason, my keyboard is locked on two machines. I get no error message, just a beep every time I try to press a key.
I'm not completely locked out, as the on screen keyboard does work.
The only time the external keyboard works [at least on my laptop], is on the lock screen, and then only on a fresh boot.
If the lock screen comes up after I have logged in, then the lock screen displays "Locked", and doesn't accept keyboard input.
What does "Locked" mean on the lock screen?