Adding a new widget class to a 3D widget causes a crash

When clicking the button to add a new class to a widget component via the [+] button the engine will crash

1. Open Editor
2. Create new Actor blueprint
   Right click content browser > Blueprint > Actor
3. Open Actor blueprint
4. Go to the components tab
5. Add a Widget Component
   Click "add component" > Type "widget" > Select widget component
6. Click the [+] looking button (see attached image) to add a widget class
7. Click ok
8. Notice the engine crashes