Light build stuck on complete Project.

Light build gets stuck at x%. x depends on the complexity of the scene. Complex scenes will get stuck at 98%, a simple Level with only a Cube and a static light will get stuck at ~25%.

I did some research and did multiple things:

  1. Deleted and validated the SwarmAgent Chache.
  2. Reimportet the SM_Template_Map_Floor.fbx into my Project. (for some strange reason this was a bug in 2014-2016)
  3. Placed and Deleted LightmassImportanceVolumes → no effect
  4. “Force no precomputed Lights” and build light → it build light and everything was black, so it worked. if i try it now, nothing seem to happen, maybe because there is no light build in the first place…
  5. resized lightmap resolution of foliage meshes
  6. set up a test scene with only one cube and a static pointlight within my project → light doesn’t build
  7. created a new project → light build works fine.

So it seems, my whole project is affected by the lightbuild stuck virus. Should i create a new Blank Project and just Migrate all my stuff there, or is this a known bug and are there some easy steps avoiding this issue?

more info:
As you can see, my lightmap density seems to be ok.
I’m building on a 16GB 8x4GHZ PC, GTX780
The Light build is finished inside swarm agent 100%, but it seems to stop then and just idle…

Thanks for your Help,
Tank :slight_smile:

Updated to 4.15.1, but still have the same Problem :frowning:

EDIT: I found the issue:

If you run into the same problem, make sure that all your Sublevels are set to “use Lightning Scenario”. Those sublevels shouldn’t be build at all, since they are hidden, but somehow they affect the building process. It was so simple, but it took me a whole day to figure out…