Having an "IsShiftDown" node with a branch in the On Key up event will cause a crash

If a user uses an IsShiftDown node inside of an OnKeyUp override it will cause the editor to crash.

1. Open the Editor
2. Create a new widget blueprint
3. Open the the new widget blueprint
4. Go to the event graph
5. Override the OnKeyUp
6. Create the blueprint in the attached image
7. Save and compile
8. Open the level blueprint
9. Create the blueprint in the second image
10. Click play in editor
11. Press any key
12. Notice that the editor crashes

Expected: Print String is applied to the screen without a crash
Result: Crash