Fixed a `NullReferenceException` when accessing mesh information from an [ARFace](xref:UnityEngine.XR.ARFoundation.ARFace) in the Editor. The exception was thrown from ``Unity.Collections.NativeArray`1[T].CheckElementReadAccess``.
[ARMeshManager](xref:UnityEngine.XR.ARFoundation.ARMeshManager) no longer throws `ArgumentNullException`s ("Value cannot be null") when exiting play mode in the editor.
Fixed Issue 1353859: During face tracking, each `ARFace` may create three additional GameObjects to represent the left eye, right eye, and fixation point. Previously, this would incorrectly create three additional, superfluous GameObjects at the origin. These additional GameObjects are no longer created.
Fixed a missing dependency on built-in particle system module.
Fixed incorrect validation in [ARMeshManager](xref:UnityEngine.XR.ARFoundation.ARMeshManager) which prevented its use in a prefab.
