Undo, Redo, and Safe Editing

Use the product window for structural edits

Add, duplicate, move, and delete Chapters and Ordered Objectives from the Chapter & Objectives window. Those commands record the relevant scene objects and serialized owners with Unity Undo, update selection, and keep the authoring context visible. Use the component Inspector for detector-specific fields and Objective Link.

Direct YAML editing, array-size changes in Debug Inspector, or manual hierarchy moves can bypass the invariants the window maintains. They are not a supported authoring workflow.

Undo can restore data; it cannot change external history

• Renaming a Title is presentation-only. Renaming an Identifier changes the key used by scene links, API calls, transitions, and persistence.
• Duplicating an Ordered Objective should produce a distinct ID. A copied scene component must be relinked to that new entry.
• Deleting an entry may leave scene components with a missing link. Undo restores the row in the scene, but a saved external file or already shipped build is outside Unity Undo.
• Reordering changes which task becomes active next. Existing component links remain ID-based rather than index-based.

Pair Unity Undo with version control

Before a large authoring change, commit or copy the scene and prefabs. After the change, inspect the scene diff for unexpected identifier churn or UnityEvent target loss. Keep generated .meta files with their assets so GUID-backed references remain stable. When upgrading the package, preserve a reversible checkpoint before opening scenes in a newer version.