Build lights in UE4.15.3 finishes but doesn't change anything

Having problem with lighting build (as usual…)!

After hours of building the lights with a 24 threads xeon and a laptop i7-6700k it finally gets to 100% and announces the completion of the lights build… and it remains exactly the same… as if nothing was done!

In swarm log I can’t get a lot of information, but I really don’t understand the problem, because there was no error!

Bare in mind that the specs were super high due to a lot of bad strategies while modeling. One mesh as 4096 lightmap resolution. I know that that’s not optimal (nor even close) however the deadline is nearing and don’t have time for major geometry changes :frowning: