Failed lighting build on mac in 5.7

Development Rendering
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1

I go to build and build lighting only, then instantly fails. I get this error: “MapCheck: Error: WorldSettings_1 Maps need lighting rebuilt”. I have assets set to static and have lumen turned off.

2

I had this problem too, it was that the swarm agent for building light didn’t work. But I could build with the GPU Lightmass plugin (you need to temporary enable Support Hardware Ray Tracing in project settings for this too)

image

4

I appreciate all your help. I made the changes you suggested and still having the same error.

Screenshot 2026-04-08 at 11.49.19
Screenshot 2026-04-08 at 11.49.191604×426 108 KB

5

What does the log say?

6

So I checked the log first and they had this line:

LogStaticLightingSystem: Warning: No importance volume found, so the scene bounding box was used. You can optimize your scene’s quality and lighting build times by adding importance volumes.

So I added an importance lightmass volume for the level. It stopped displaying that line.

Then here is the log running with the lightmass volume over all the objects not including the :

ogEOSSDK: LogEOS: Updating Product SDK Config, Time: 1301.214600
LogEOSSDK: LogEOS: SDK Config Product Update Request Completed - No Change
LogEOSSDK: LogEOS: ScheduleNextSDKConfigDataUpdate - Time: 1301.880005, Update Interval: 325.459106
LogEOSSDK: LogEOS: Updating Product SDK Config, Time: 1647.325562
LogEOSSDK: LogEOS: SDK Config Product Update Request Completed - No Change
LogEOSSDK: LogEOS: ScheduleNextSDKConfigDataUpdate - Time: 1647.426147, Update Interval: 301.532257
LogStaticLightingSystem: Running Lightmass w/ ImmediateImport mode ENABLED
LogStaticLightingSystem: Running Lightmass w/ ImmediateProcess mode ENABLED
LogStaticLightingSystem: Running Lightmass w/ Sorting mode ENABLED
LogStaticLightingSystem: Running Lightmass w/ Mapping paddings ENABLED
LogStaticLightingSystem: Running Lightmass w/ Mapping debug paddings DISABLED
LogEditorBuildUtils: Build time 0:00
LogUObjectHash: Compacting FUObjectHashTables data took 0.18ms
LogStaticLightingSystem: Warning: Failed to build lighting!!! Lighting build failed.
DumpUnbuiltLightIteractions
Lights with unbuilt interactions: 1
Light Light Source
Primitives with unbuilt interactions: 66

…(goes through the assets in the scene)…

(ends with)

Cmd: MAP CHECK NOTIFYRESULTS

MapCheck: Error: WorldSettings_1 Maps need lighting rebuilt