Bones not listed in Connected Bones dropdown

REGRESSION:
Yes, does not occur in 4.15.

In Persona, no bones appear in the Connected Bones dropdown.

Also occurs in Main CL 3298251.

1. Open QAGame in editor.
2. Open the animation TestMorph.
3. Open the Anim Curves window.
4. Select a curve.
5. In the Details panel, click the plus button for Connected Bones.
6. Click the dropown that appears.

RESULT
No bones are listed.