Recast Graph Scan: "This should not happen" error occurs

General
1

I am seeing an error of “This should not happen” when I try and scan a recast graph with a walkable climb above .5.

The error occurs multiple times and the stack is as follows. Any ideas on a fix for this?

This should not happen
UnityEngine.Debug:LogError(Object)
Pathfinding.Voxels.Voxelize:WalkContour(Int32, Int32, Int32, UInt16[], List`1) (at Assets/AstarPathfindingProject/Generators/Utilities/Voxels/VoxelContour.cs:803)
Pathfinding.Voxels.Voxelize:BuildContours(Single, Int32, VoxelContourSet, Int32) (at Assets/AstarPathfindingProject/Generators/Utilities/Voxels/VoxelContour.cs:117)
Pathfinding.RecastGraph:BuildTileMesh(Voxelize, Int32, Int32) (at Assets/AstarPathfindingProject/Generators/RecastGenerator.cs:1433)
Pathfinding.RecastGraph:ScanAllTiles(OnScanStatus) (at Assets/AstarPathfindingProject/Generators/RecastGenerator.cs:1293)
Pathfinding.RecastGraph:ScanTiledNavmesh(OnScanStatus) (at Assets/AstarPathfindingProject/Generators/RecastGenerator.cs:1202)
Pathfinding.RecastGraph:ScanInternal(OnScanStatus) (at Assets/AstarPathfindingProject/Generators/RecastGenerator.cs:1192)
AstarPath:ScanLoop(OnScanStatus) (at Assets/AstarPathfindingProject/Core/AstarPath.cs:1827)
AstarPathEditor:MenuScan() (at Assets/AstarPathfindingProject/Editor/AstarPathEditor.cs:2429)
AstarPathEditor:OnInspectorGUI() (at Assets/AstarPathfindingProject/Editor/AstarPathEditor.cs:452)
UnityEditor.DockArea:OnGUI()

2

Yeah, that is a long term bug which, contrary to what the error says, does actually happen sometimes (very special edge cases world geometry). Look at the navmesh and see if it looks ok, then it is likely not a problem. If it persists, try changing the cell size by small amounts.

3

I have experimented with this, and I can get it to a single instance of the “this should not happen” error. The mesh data looks fine, so it won’t have any other unintended side effects when pathing?

4

If the graph looks fine, then it’s usually no problem. That error can sometimes cause parts of the graph to look a bit weird.