Well, I have never ran into this either. So, I checked with my resident expert at Arctic Spas, and basically pack protection from getting stuck relays for the pumps. Here is exactly what he said in my email:
Attached is what the error means. It was protection from stuck relays before there were redundant relays.
It shows this "error" on start-up. Pressing any key gets rid of it... its just informational. If his water ever does overheat then It would be reasonable to guess that his pump 2 relay has been sticking (based on "A9" - its almost never Pump 1 as it has a low speed and hence a "soft start:).
Its a confusing one but in short - reset the breaker, push a button to clear that message and everything should work fine.
So, I know you said you hit the temperature buttons, but you might try pressing pump one or two. If all of that doesn't work, then I am guessing something must be wrong with the spa pack, and most likely will need replaced. But, try these steps first to see what it does. Hopefully that will work.