Currently, when a new ScrollBar Template is created in Standalone, it will generate a PART_Track containing an:

• IncreaseRepeatButton
• DecreaseRepeatButton
• Thumb

However, when a ScrollBar Template is created in Studio Unreal, duplicates of each other above will be created.

If you have trouble reproducing this, please ping @Dorian -- can send you a Project in which this happens 100% of the time.

Repro Steps:

1) Create a new Studio Unreal Project containing a MainPage.xaml.

2) Introduce a ListBox to the Page, and save a ListBox Template, saved to GlobalResources.xaml

3) In Unreal's NoesisGUI Toolbar/Settings, set GlobalResources.xaml as the Project's Dictionary.

4) Within the ListBox Template created in Step 2), create a Template for the default ScrollViewer in the ListBox Template.
This will open the ScrollViewer Template in the Inline Dummy Template Editor.

4) Create a Template for the PART_VerticalScrollBar.
This will open the PART_VerticalScrollBar Template in the Inline Dummy Template Editor.

Observe how there are duplicates of each Part of the Template.

Expected Results: A ScrollBar Template includes only one of each Part of the Template.