Repro Steps:

1) Create a Page
2) Using the Path Tool, draw a fully-enclosed triangle.
3) Using the Path Selection tool (A), select any anchor point on the path.
4) Ctrl+Click the anchor point to convert it to a curved angle, and to expose its anchor point handles.
4) Modify any of its handles, to any position, then once that has been completed, in its properties, set its Mirroring Mode to 'Mirror Angle'.
5) Drag the handle of the anchor point, directly to the anchor point itself.

Observe the Path disappearing from view, and any further action usually resulting in an application crash.

Expected Results: Changing the position of anchor point handles doesn't crash Studio.