This way of switching the fence on by itself is being retired

What ArduPilot says:

• FENCE_AUTOENABLE is N, will be removed in 4.7, use 3

FENCE_AUTOENABLE is 1 (the fence goes on after an automatic take-off and off for an automatic landing) or 2 (the same, but only the minimum-altitude fence goes off for landing). The developers intend to remove both values, and the arming check repeats this line once a minute to say so. Arming is not blocked. In 4.7.1 both values still work, and the line still says “will be removed in 4.7”.

What to do, most likely first

1. FENCE_AUTOENABLE is 1 or 2.

   CheckAfter the change, arm once on the ground and look for a line such as “Max Alt and Circle fences auto-enabled”.

   FixSet FENCE_AUTOENABLE to 3: every selected fence except the minimum altitude goes on at arming and off at disarming, and the minimum altitude turns on once the aircraft has climbed above it. Or set it to 0 and keep the fence on all the time with FENCE_ENABLE 1.

Parameters to look at

Where to do it:Failsafe Explainer