Building Light stuck at 75%

I have deleted saved and intermediate and the Unreal Engine local app data.

I have opened swarm agent and cleaned cache and validated.

No matter what, building light will reach 75% and will never progress.

I had the same issue (but at 66%), but it somehow did go away. I had invalid blueprints on some maps, which I fixed. Maybe that was it.

Hello Dannyk90,

From what you described it sounds like your lightmass is building while your lighting build gets stuck and doesn’t complete it’s build.

I have a little information I would like to receive from you in order to narrow down what could be causing this.

If you would send me a link of your DxDiag, I will see if there is an issue that is native to your computer.
Does this happen in 4.8?
Is this in a project that was copied from 4.8 to 4.9?


It has been working before, all I have done is add a new level with a light.

This is a 4.9 only project.

link text

thank you .

This appears to be another issue where the Lightmass is running but the build gets stuck at different percentages.

The bug number currently associated with this bug is UE-20782.

Thank you very much for reporting this issue.

I will keep you p to date with it’s progress.