NullReferenceException whenever trying to save a blackboard in Unity 2023

[MishterKirby]

When using Open Behavior Trees under Unity 2023.3.0b2, the following output gets generated when clicking save on a behavior tree blackboard

NullReferenceException: Object reference not set to an instance of an object
OpenBehaviorTrees.BehaviorTreeEditorUtilities.GenerateAssetCopy (OpenBehaviorTrees.BehaviorTreeNode currentNode, OpenBehaviorTrees.BehaviorTreeNode parent, System.Collections.Generic.Queue`1[T] order) (at ./Library/PackageCache/com.sterberino.open-behavior-trees/Editor/BehaviorTreeEditorUtilities.cs:231)
OpenBehaviorTrees.BehaviorTreeEditorUtilities.GenerateAssetCopy (OpenBehaviorTrees.BehaviorTreeNode currentNode, OpenBehaviorTrees.BehaviorTreeNode parent, System.Collections.Generic.Queue`1[T] order) (at ./Library/PackageCache/com.sterberino.open-behavior-trees/Editor/BehaviorTreeEditorUtilities.cs:215)
OpenBehaviorTrees.BehaviorTreeEditorUtilities.GenerateAssetCopy (OpenBehaviorTrees.BehaviorTreeNode currentNode, OpenBehaviorTrees.BehaviorTreeNode parent, System.Collections.Generic.Queue`1[T] order) (at ./Library/PackageCache/com.sterberino.open-behavior-trees/Editor/BehaviorTreeEditorUtilities.cs:224)
OpenBehaviorTrees.BehaviorTreeEditorUtilities.GenerateTreeFromNode (OpenBehaviorTrees.BehaviorTreeNode node) (at ./Library/PackageCache/com.sterberino.open-behavior-trees/Editor/BehaviorTreeEditorUtilities.cs:110)
OpenBehaviorTrees.BehaviorTreeEditorWindow.Save () (at ./Library/PackageCache/com.sterberino.open-behavior-trees/Editor/BehaviorTreeEditorWindow.cs:1071)
OpenBehaviorTrees.BehaviorTreeWindowHeader.Render (UnityEngine.Rect position, System.Single sidebarWidth) (at ./Library/PackageCache/com.sterberino.open-behavior-trees/Editor/BehaviorTreeWindowHeader.cs:63)
OpenBehaviorTrees.BehaviorTreeEditorWindow.OnGUI () (at ./Library/PackageCache/com.sterberino.open-behavior-trees/Editor/BehaviorTreeEditorWindow.cs:235)