When the venue's sign-in is refused for a reason that is not a wrong PIN, the whole screen says so, with Try again and Pair this terminal again.
billing inactiveThe venue's plan lapsed. Fix billing on the dashboard; then Try again.
revokedAn owner removed this device on the dashboard, or it failed the device check three times. Pair again.
device mismatchThe credential does not match this machine. A copied config file does this. Pair again.
Nothing on the till is lost; drafts are on the server.
Related: Session expired mid-shift · Pair a terminal with a 6-digit code