I am somewhat new to the hobby, I've flown a couple planes. Right now I'm building one from a kit, but after turning on the ESC it wasn't working correctly. When the throttle from the transmitter is at 100% the ESC thinks it's at 0%, and vice versa for when the Throttle is at 0%. I am probably being stupid, but I haven't found any way to fix this online.

I'm using the Skywalker 40A UBEC as my ESC, and the AT9S as my transmitter.