Exception in 4.3.47 using UpdateGraphs

I recently attempted to upgrade a project that’s been happily using an older version of this plugin (4.2.8) to the beta, but ran into some breaking issues. This is a “large open world” type of game that generates the navmesh at runtime, using a series of UpdateGraph calls on two RecastGraphs.

While smaller pieces of the world can work, if I try to generate the entire thing I eventually get this exception, which stops the process:

NullReferenceException: Object reference not set to an instance of an object
Pathfinding.HierarchicalGraph.JobRecalculate () (at Assets/Plugins/Packages/com.arongranberg.astar@4.3.47/Core/Misc/HierarchicalGraph.cs:240)
Pathfinding.HierarchicalGraph.RecalculateIfNecessary () (at Assets/Plugins/Packages/com.arongranberg.astar@4.3.47/Core/Misc/HierarchicalGraph.cs:280)
Pathfinding.WorkItemProcessor.EnsureValidFloodFill () (at Assets/Plugins/Packages/com.arongranberg.astar@4.3.47/Core/Misc/WorkItemProcessor.cs:245)
Pathfinding.WorkItemProcessor.ProcessWorkItems (System.Boolean force, System.Boolean sendEvents) (at Assets/Plugins/Packages/com.arongranberg.astar@4.3.47/Core/Misc/WorkItemProcessor.cs:331)
Pathfinding.WorkItemProcessor.ProcessWorkItemsForUpdate (System.Boolean force) (at Assets/Plugins/Packages/com.arongranberg.astar@4.3.47/Core/Misc/WorkItemProcessor.cs:381)
AstarPath.PerformBlockingActions (System.Boolean force) (at Assets/Plugins/Packages/com.arongranberg.astar@4.3.47/Core/AstarPath.cs:885)
AstarPath.Update () (at Assets/Plugins/Packages/com.arongranberg.astar@4.3.47/Core/AstarPath.cs:868)

(after this I also get a lot of “Please do not wait for other work items to be completed inside work items” spam)

This is on Unity 2020.3.25f1.


Thank you for reporting this.
I haven’t been able to replicate it. Would it be possible for you to share a small example project which shows the bug?