I don't know how much work the idea I'm about to propose would be compared to fixing all the nav mesh, but in my head it's more like painting the terrain with a broad brush rather than finding a needle in a haystack. Would it be possible to put tags on sections of the nav mesh (for simplification, we'll just use A, B, and U). So when you attempt to shadowstep, instead of trying to find a path along the nav mesh, it'll look at the tags at the start and end location. So if you're standing on a piece of ground tagged "A" and attempt to shadowstep to a part of ground also tagged "A" it will automatically succeed and teleport you there more like how portal works (ignoring the actual path in between the two). If you try to shadowstep from a place tagged "A" to a place tagged "B" it will default to the current path finding mechanic, and if a successful path is found, it will shadowstep you. This second check would be due to stuff like the inside of keeps and tops of walls in WvW, and inside the lord area of foe fire in PvP needing to be tagged differently from the outside of them to prevent going through walls. This would narrow your hunt for broken nav mesh down to only where changes in the nav mesh tags occur. Alternatively, instead of the current pathing check to see if a wall or gate is down, have a trigger that when a wall or gate is destroyed, it applies a universal beginning and end to a shadowstep in a 2k radius around the piece of terrain. So the way it would work then is if a wall is destroyed, in a 2k radius around it, the nav mesh would be tagged "A&U" on the outside of the keep and "B&U" on the inside. The "A to B" check would fail, but the "U to U" check would succeed, triggering a successful shadowstep. I have no idea what your code looks like and how hard it would be to add a new script to do this check of shadowstep abilities, but it seems simpler than looking for all the wrinkles and disconnects in the mesh. Edit: P.S. I will try to document problems when I find them though to help with your search.