So some info on reading the error messages. The monster name is "vescavor swarm" and its Unique ID is "rVescaSwrm" and it has no "CB" or "AP78" in it which means its from LW. If it was community created it would have been like "rCBVescSwr" or "rAP78VeSw" in example.
So if we look up "
Vescavor Swarm" on d20pfsrd we see its from "Pathfinder Campaign Setting: Lost Kingdoms".
So you will need that Official package to correctly open up the .por file.
