Opening Montage hangs UE4Editor

Editor experiences an unrecoverable hang when placing the user's Montage into a Third Person Blueprint Project and opening the montage after retargeting to the current skeleton.

Attached Log from Project as well as Visual Studio Debug Logs

1. Create a New Third Person Blueprint Project with NO Starter Content
2. Add the attached Montage *.uasset to the project's content folder
3. In Editor, double click new Montage Asset
4. Retarget to UE4_Mannequin_Skeleton

RESULTS: Editor Hangs with no way to recover besides force closing application

EXPECTED: Editor to not Hang not crash, throw a warning and not allow you to open Montage if that is the issue at hand.