Copter: landing detector internal error in Stabilize mode

[rmackay9]

How to reproduced the problem:

• Upload Copter-4.5 (or higher) to an autopilot
• set DISARM_DELAY 0 (to disable automatic disarming while landed)
• switch vehicle to Stabilize mode
• arm the vehicle
• raise throttle to 100%
• turn autopilot upside down

"Internal Error 0x100000" should appear on the GCS's messages tab as shown below (please ignore the "land_complete:xx" debug messages added during the investigation of this issue).

The code that triggers this error is here in land_detector.cpp. Another related line in mode_stabilize.cpp is here.

This issue was first reported here in the Copter-4.5 support forums.