Sometimes a print has infill then an incomplete top layer. IE the top layer is only on a portion of the model.
problem comes when the top layer "ends" in one of the holes in the infill the filement can "fall in"
a solution is to add more infill but that is such a waste of both time and plastic.
how do I get (or can it be added) to ADD a bridge when this happens it is easier to describe in video form
https://www.youtube.com/watch?v=XEES-4SybLA