Lighting will not build

After bringing a map from 4.17 into 4.18, the lighting will not rebuild. Here’s what happens:

BuildLighting Only → (build status prompt) → (no window for about 30 seconds) → “Map check found some errors!”

Map check error:

“WorldInfo_0 Maps need lighting rebuilt”

Lighting results:

“InstancedFoliageActor_0 The total lightmap size for this InstancedStaticMeshComponent is large, consider reducing the compnoent’s lightmap resolution or number of mesh instances in this component
InstancedFoliageActor_0 Instanced meshes don’t yet support unique static lighting for each LOD. Lighting on LOD 1+ may be incorrect unless lightmap UVs are the same for all LODs.”

I have shadows disabled on all my foliage and lighting did build fine in the previous version.

Thank you

As an update, the lighting builds after I delete the foliage. Wouldn’t call it a solution, but it is the cause of the problem.

Make SURE you go into World Settings and UnCheck “Force No Computed Lightmaps” as this can cause the same error you’re receiving about lighting failed.

“Force No Computed Lightmaps” was unchecked when I had the issue. It ended up being a foliage actor that had a count too large. It may be a bug but haven’t tried to replicate it. I ended up deleting that one foliage actor and redoing it in the new version. It had a similar count as the previous time but it allowed me to bake the lighting after doing this.

I’m having this same issue, anyone have a solution? I’m using 4.18. It’s on a new map that was created in 4.18, but on a project that was updated from 4.17

worked for me