Hey @PrizmIzm
Mystery is solved.
I’ve uninstalled and re-installed UE4, latest version. Applied Luoshs’ GPULM and run your modified project.
I rendered it at preview quality and it worked!
I took it to Extreme quality with fireflies at 10 and the light was gone (!!?!!!?!!???!!!)
I took back the fireflies to 10000 and the light from HDRI was back as it was.
So:
Light from HDRI + fireflies at 10 = not happening as the light from HDRI just disappears.
No idea but if we want HDRI light we’ll have fireflies…! So for now we’ll skip HDRI light unless mighty can do something about it!