Something has gone wrong with your landing. If doing an AUTOLAND, the auto throttle should disengage. This obviously isn't happening.

It has happened to me if I pulled back on the joystick to try to make the landing smoother/softer. That seems to prevent the A/P and A/T from disengaging. It's best to let it land on its own or to actually land using the VREF and not VREF+5.