On the front of the CPU the "stat" light is red. In the hardware user manual it shows that there should be an "err" light at this location. If the "err" light is red then "CPU fatal error"
The Terminator CPU only has 6 LEDs on it, so we ended up using the ERR LED for something additional (battery, I think) so we changed the label to STATus. It is the same function as before, but I guess the manual needs a touch up.
We're looking into why the I/O status view isn't showing what I believe to be an I/O mismatch. It should be...