I’ve made a wall light mesh, and placed a pointlight inside the mesh. There are no triangles facing inward, so no shadow should get cast. And this worked in 4.15, but now that I’ve migrated to 4.16, it seems that the backface of the mesh is blocking shadows, but only when I’m within about 800 units of the light. Here is the lighting properties for the static mesh (on my BP)
I made no changes between 4.15 and 4.16, so I’m not sure why its suddenly casting shadows. It looks to shadow properly in the BP viewport.