Tailsitter or tiltrotor was enabled after start-up

What ArduPilot says:

• PreArm: tailsitter setup not complete, reboot
• PreArm: tiltrotor setup not complete, reboot

Q_TAILSIT_ENABLE or Q_TILT_ENABLE is above 0, but that part of the code was not started. It is started once only, with the rest of the VTOL code at power-on, because it replaces the logic that handles transitions (the change between hovering and flying on the wing). Until a reboot the aircraft would transition like a plain QuadPlane, so arming is refused.

What to do, most likely first

1. The enable parameter was changed after the flight controller started.

   FixReboot the flight controller, then refresh the parameter list: the tailsitter or tiltrotor parameters appear after it.

Parameters to look at