I migrated the god beam blueprint from the unreal blueprint office level into my own - however when I drag out the blueprint in my own level nothing happens - there is no beam.
I then migrated the blueprint into a new basic example level and it works fine!?
You won’t be able to see the light beam as easily in a well lit scene like that. To debug this try opening the BP_LightBeam in the Blueprint Editor and looking at the viewport. If you can see the lightbeam working there it’s working in your level/project. There are some stipulations that make it easier to see where there is occlusion of light above and moving it under this area to better see the results. Think like an area where an open window is. In your first image using the Unlit lighting view and having a lot of light colored areas behind will probably not make it easy to see.