'Bad GPS Pos' error

I am trying to track down what causes the ‘Bad GPS Pos’ error on MP, but cannot find any documentation explicitly stating what that feedback is tied to (Number of satellites? HDOP (or other DOP) value?)

Would anybody be able to shed some light on what produces that error? Or the piece of documentation that does detail it?


Apologies, erroneously posted this in the Mission Planner forum instead of the APM forum (hooray similar names) feel free to delete this thread!