I am having this problem since about 4.15 I think. I was able to build no problem before that but now it does 0% then fails. I just deleted all assets from my scene except the player, a directional light and a ground static mesh and it still fails. Every map I have in the project I am working on. I have opened other projects and it builds. I have tried firewall on firewall off…deleting sworm cache …deleting saved and intermediate folders… all I get is:
LogStaticLightingSystem:Warning: Failed to build lighting!!! Lighting build failed.
DumpUnbuiltLightIteractions
Lights with unbuilt interactions: 0
Primitives with unbuilt interactions: 0
Not sure what to do. I have like a years worth of work and I can’t build the lights… 