Auto mission error?

Transferred as DO_SET_ROI · DELAY· Waypoint in the auto mission, advancing in the direction of ROI with auto flight ON and rapidly lowered the altitude.

Continue and crashed.

I tried it twice, but the result was the same.

APM2.4.6 Ver3.5.2
Mission Planner Ver 1.3.55(build 1.3.660.28588)

Post dataflashlog if you want anybody to be able to help.