It means it is not getting any water in. Check taps are fully open. Take inlet hose off the inlet valve & check the inlet valve filter. The filter may be blocked. While the hose is off the back of the machine, point it in to the sink & turn on tap to see if there is a strong flow. If water & filters are ok & fault reappears then you may need to change the inlet valve for a new one.
Lincoln Appliance NZ, November 2009