Recast Graph Errors - Unable to razterize Colliders

Hi,
was impressed and just got the Astar Pathfinding pro version and really want to use the recast graph. One problem. I am unable to rasterize colliders. Whenever I tick that option and click scan I get the below errors:

There was an error generating the graphs:
System.NullReferenceException:
at (wrapper managed-to-native) UnityEngine.Mesh:get_vertices ()
at Pathfinding.RecastGraph.RasterizeCollider (UnityEngine.Collider col, Matrix4x4 localToWorldMatrix) [0x0046e] in C:\Users\Gam400\Desktop\FromScratch\Assets\AstarPathfindingProject\Generators\RecastGenerator.cs:1108
at Pathfinding.RecastGraph.RasterizeCollider (UnityEngine.Collider col) [0x00000] in C:\Users\Gam400\Desktop\FromScratch\Assets\AstarPathfindingProject\Generators\RecastGenerator.cs:961
at Pathfinding.RecastGraph.CollectMeshes (UnityEngine.MeshFilter[]& filters, .ExtraMesh[]& extraMeshes) [0x00323] in C:\Users\Gam400\Desktop\FromScratch\Assets\AstarPathfindingProject\Generators\RecastGenerator.cs:888
at Pathfinding.RecastGraph.Scan () [0x00016] in C:\Users\Gam400\Desktop\FromScratch\Assets\AstarPathfindingProject\Generators\RecastGenerator.cs:451
at AstarPath+c__Iterator9.MoveNext () [0x00237] in C:\Users\Gam400\Desktop\FromScratch\Assets\AstarPathfindingProject\Core\AstarPath.cs:1553
at AstarPath.MenuScan () [0x000d7] in C:\Users\Gam400\Desktop\FromScratch\Assets\AstarPathfindingProject\Core\AstarPath.cs:1479

Any help would be greatly appreciated.