Can't build lighting with duplicated Blueprints in scene

I’m having an unusual problem with my game.

I have a set of Blueprints of lights (mesh + point light). If I duplicate any of them in scene, the lighting fails to build (gets stuck on %100). But, if I place 1 each of the Blueprints into the scene, the lighting builds fine.

If I duplicate the Blueprint in my content browser, then add the new identical light into the scene, it builds fine. Also, if I delete the point light from the Blueprint, I can duplicate it in scene and lighting builds fine.

I’m using UE4.

Can anyone help me with this?