I upgraded my octoquad (X8 config, 15" props, Pixhawk1, external GPS+compass) from arducopter/Nutx version 3.3 to the latest Chibios 3.6.
Nothing else changed or was modified.
In the Nutx 3.3 version, the ship fly wonderfully in all modes. Never had an issue.
After upgrading to Chibios 3.6 (latest stable release from mission planner), I redid the usual : compass, accel, radio, battery monitoring calibration (incl compassmot).
I did not recalibrate the ESCs as it should not be necessary (or am I wrong ?)
Then at first manually controlled take off (in stabilize mode), the drone flipped (rolled to the right) upside down (Breaking all of the props of course).
I looked at the log but could not find any issue or explanations. I rechecked after the crash the way the props were mounted to verify if any props was inverted. All props were correctly installed and no motor or mounts were defective.
So i really do not know what happened here and I would like the help of the Community to analyze what happened.
Attached the log of the incident
2019-08-14 11-16-58.bin (263.1 KB)