Error Message "Err: navigation-5"

Ground Control Software Mission Planner
1

Hi I got a never seen error Message in a log file: “Err: navigation-5”
I could not find an answer what this means.
Has someone seen it before?

2

Ardupilot source code is your friend.

#define ERROR_SUBSYSTEM_NAVIGATION 22
#define ERROR_CODE_DEST_OUTSIDE_FENCE 5

3

Thank you that make sense.