Never came across this before. I followed a documentation on world partitioned navmesh and when i wanted to package and test it i got this error. Is there a way to solve this error?
When using navmesh on a world partitoned map you use a NavMeshBoundsVolume which also spawns in a RecastNavMesh.
If i remember corretly, I deleted my NavMeshBoundsVolume then placed another NavMeshBoundsVolume. Did so a couple of times while testing the level.
The world partitioned level will then always spawn a RecastNavMesh with the new NavMeshBoundsVolume and set the old RecastNavMesh as unloaded. Trying to build the navmesh paths will then result with the following error,
To solve it open your world partitioned level. Look into your Outliner window and you should find a unloaded RecastNavMesh. Right click it and copy file path. Paste it into your explorer and you will find where it’s located in your project ExternalActor folder. Simply delete it and restart your project then the error should be solved.
In the map you can also go to Tools → Validate Data… It will delete the files and you won’t see them anymore once restarting the editor. Also disable the automatic creation of the navigation stuff so it doesn’t happens again.