Actually, I have tried several versions of the firmware, including the very latest but still have that same error message when I try to calibrate the ESC with Mission Planner. To get around that, I've manually calibrated the ESC (Emax 4in1) directly attached to the receiver and it works just fine. However, going back to Mission Planner to calibrate the ESC still produces the same error message. But the motors will spin up when throttle is applied. But the latest firmware installation causes my motors to disarm if throttle isn't applied withing 15 seconds. That's really annoying. I've read that there's a parameter called LANDING_DISARM_DELAY...or something like that that can be set to zero through the CLI...but there's no CLI in the latest firmware and that parameter doesn't show up in the advanced tuning parameter list. Using older firmware (AC3.3.1) with my manual ESC calibration, I can get the motors to stay armed.
I just don't understand why I get that param error message when using all the latest firmware and if I ignore it, how can I stop that automatic disarming?
BTW,,,the controller is APM2.6. Does that make a difference?