I was trying to figure out why my navmesh wouldn't generate properly and after adding and then also after removing a nav volume and/or a pathnode.
This is the last thing to show in the console:
begin navmesh generation...
Umbra Tome Triggers: 0 total
tome "__default__", UMBRA volume NOT set - defaulting to = -1000000.0,-1000000.0,-1000000.0 ---> 1000000.0,1000000.0,1000000.0
UMBRA smallest_occluder=72.000 small_hole=4.000