Static Mesh Editor and Persona viewport are very dark

The default viewport look for Persona and Static Mesh Editor is very dark, and the preview mesh is barely visible.

It seems like the Directional Lighting settings aren't doing anything. Maybe it was removed by accident.

I could not reproduce this issue in UE4/Main. It's much brighter.

1. Open QAGame in editor.
2. Open a skeletal mesh in Persona.

RESULT:

Viewport is very dark by default