Repro Steps:

1) Create a new Project.
2) Within MainPage.xaml, in the Root Grid, select the PenTool [P]
3) Using the Pen tool, place two anchor points to create a segment.
4) Press [Esc] to exit the Segment created in Step 3).
5) With the Pen Tool, click anywhere on the Stage that is not along the segment created in Step 3) and Step 4). This will create a new anchor point.
6) Press Ctrl+Z to remove the anchor point placed in Step 5).

Observe Studio crashing.

Expected Result: The placement of a new anchor point can be undone without crashing the application.