Currently, if you create a Template from the Properties Panel from within a Style, and then you undo all changes across the entire Project, the original Template will be invisible until the Page its used in is closed and re-opened.

Video attached.

Repro Steps:

1) Open the WorldUI_UnityDemo Project from the GitHub InternalProjects repo, in Noesis Studio (/Assets/WorldUI/WorldUI.noesis)

2) In the ObjectPanel.xaml, right click on the orange button in the middle of the Page, and from its context menu, navigate to 'Styles'-->'Edit Current'.
This will open the Style in the Style Dummy Editor, as seen by the orange border around the Stage.

3) From the Style's Properties Panel, navigate to the 'Templating' Section, and on the 'Template' Property, click the (+) icon to the right of its dropdown to create a new Template in place.

4) Name the new Template as desired, and select any save location for it.
This will apply the new blank Template on-Stage, and open it in the Dummy Template Editor as seen by the magenta Stage border.

5) Exit back to the Page by pressing the House icon in the upper-left of the Stage.
Observe what previously used to be a sci-fi graphic is now blank. This is expected.

6) Undo all changes made since starting these repro steps by either pressing Ctrl+Z repeatedly, or from the Hamburger Menu and navigating to 'Edit', then 'Undo' and repeating this repeatedly.
Once the document has been restored to its initial and original state can be noted by the asterisks in any open tabs ceasing to be displayed once that point is reached.

7) At this point, due to returning to the Style Dummy Editor in the process, its possible that in the 'undo' process, you may have to press the 'Home' icon again to return to the active Page.

Observe how despite undoing the new Template application, and undoing the new Template creation, the original sci-fi graphics have not returned to the Page.

7) Close and re-open ObjectPanel.xaml.

Observe how the sci-fi graphic has returned.

Expected Results: Changes to a document are accurately reflected in the viewport.