Consistently crashing after successfully building lighting


I am consistently crashing after ‘successfully’ building lighting (not really a success since it crashes before it saves). I have deleted all contents of saved, and intermediate folders. I have set tdrdelay to 60 seconds. I have cleaned the cache of swarm agent and set cache size to 100gb.

I am honestly not sure what is causing the issue, I’ve ran build lighting only several timers before with much longer build times and not crashed.

I have a 2080, i7 9700k, 48gb RAM. Graphics drivers up to date.

My resolution is at 3440x1440.

I am on windows 10 pro using insider preview.

I will post logs below although I’m not sure if this is the correct logs.

Any help would be greatly appreciated.

[2020.07.16-13.19.15:034][239]MapCheck: New page: Map Check
[2020.07.16-13.19.15:045][239]LightingResults: New page: Lighting Build - 16 Jul 2020, 15:19:15
[2020.07.16-13.19.15:220][239]LogSwarmInterface: [OpenConnection] Registering TCP channel …
[2020.07.16-13.19.15:226][239]LogSwarmInterface: [OpenConnection] Connecting to agent …
[2020.07.16-13.19.15:234][239]LogSwarmInterface: [TryOpenConnection] Testing the Agent
[2020.07.16-13.19.15:245][239]LogSwarmInterface: [TryOpenConnection] Opening Connection to Agent
[2020.07.16-13.19.15:245][239]LogSwarmInterface: [TryOpenConnection] Local Process ID is 11076
[2020.07.16-13.19.19:857][239]LogStaticLightingSystem: Running Lightmass w/ ImmediateImport mode ENABLED
[2020.07.16-13.19.19:857][239]LogStaticLightingSystem: Running Lightmass w/ ImmediateProcess mode ENABLED
[2020.07.16-13.19.19:857][239]LogStaticLightingSystem: Running Lightmass w/ Sorting mode ENABLED
[2020.07.16-13.19.19:857][239]LogStaticLightingSystem: Running Lightmass w/ Mapping paddings ENABLED
[2020.07.16-13.19.19:857][239]LogStaticLightingSystem: Running Lightmass w/ Mapping debug paddings DISABLED
[2020.07.16-13.19.20:240][239]LogEditorBuildUtils: Build time 0:05
[2020.07.16-13.19.21:455][272]LogUObjectHash: Compacting FUObjectHashTables data took 1.56ms
[2020.07.16-13.19.27:077][288]Job is a success!
[2020.07.16-13.19.27:422][289]LogSlate: Took 0.000121 seconds to synchronously load lazily loaded font ‘…/…/…/Engine/Content/Slate/Fonts/Roboto-Light.ttf’ (167K)
[2020.07.16-13.19.27:942][289]LogVolumetricLightmapImport: Imported Volumetric Lightmap in 0.423s
[2020.07.16-13.19.27:942][289]LogVolumetricLightmapImport: Indirection Texture 32x32x16 = 0.1Mb
[2020.07.16-13.19.27:942][289]LogVolumetricLightmapImport: BrickData (all levels) 0.1Mb (trimmed 0.8Mb due to 0.010000 MinBrickError)
[2020.07.16-13.19.27:942][289]LogVolumetricLightmapImport: Bricks at depth
[2020.07.16-13.19.27:942][289]LogVolumetricLightmapImport: 0: 14.8% covering 100.0% of volume
[2020.07.16-13.19.27:942][289]LogVolumetricLightmapImport: 1: 81.5% covering 8.6% of volume
[2020.07.16-13.19.27:942][289]LogVolumetricLightmapImport: 2: 3.7% covering 0.0% of volume
[2020.07.16-13.19.27:942][289]LogVolumetricLightmapImport: Bricks in each level
[2020.07.16-13.19.27:942][289]LogVolumetricLightmapImport: 1_Main 27 bricks 100.0% (Persistent Level)
[2020.07.16-13.19.29:426][289]LogTexture: Display: Building textures: HQ_Lightmap1_1 (AutoDXT, 1024X1024)
[2020.07.16-13.19.29:426][289]LogTexture: Display: Building textures: LQ_Lightmap_1_1 (DXT1, 1024X1024)
[2020.07.16-13.19.29:426][289]LogTexture: Display: Building textures: HQ_Lightmap1_2 (AutoDXT, 1024X1024)
[2020.07.16-13.19.29:426][289]LogTexture: Display: Building textures: LQ_Lightmap_1_2 (DXT1, 1024X1024)
[2020.07.16-13.19.29:426][289]LogTexture: Display: Building textures: HQ_Lightmap1_3 (AutoDXT, 1024X1024)
[2020.07.16-13.19.29:426][289]LogTexture: Display: Building textures: LQ_Lightmap_1_3 (DXT1, 1024X1024)
[2020.07.16-13.19.29:572][289]LogTexture: Display: Building textures: ShadowMapTexture2D_1 (BGRA8, 1024X256)
[2020.07.16-13.19.29:572][289]LogTexture: Display: Building textures: ShadowMapTexture2D_0 (BGRA8, 1024X1024)
[2020.07.16-13.19.29:572][289]Lightmass on DALELIVINGROOM: 7.42 sec total, 535 ms importing, 94 ms setup, 1.10 sec photons, 5.65 sec processing, 0 ms extra exporting [280/280 mappings]. Threads: 39.6 sec total, 15.6 sec processing.
[2020.07.16-13.19.29:573][289]LogStaticLightingSystem: 1_Main_BuiltData storing lightmap data for 280 meshes in 7 LightmapResourceClusters (40.0 Meshes per cluster).
[2020.07.16-13.19.29:592][289]LogUObjectHash: Compacting FUObjectHashTables data took 1.51ms
[2020.07.16-13.19.29:607][289]LogStaticLightingSystem: Illumination: 14.2 sec (440 ms encoding lightmaps, 124 ms encoding shadowmaps)
[2020.07.16-13.19.29:607][289]LogStaticLightingSystem: Lightmap texture memory: 6.0 MB (6.0 MB streaming, 0.0 MB non-streaming), 6 textures
[2020.07.16-13.19.29:607][289]LogStaticLightingSystem: Shadowmap texture memory: 6.7 MB (6.7 MB streaming, 0.0 MB non-streaming), 2 textures
[2020.07.16-13.19.30:867][289]Lights with unbuilt interactions: 0
[2020.07.16-13.19.30:867][289]Primitives with unbuilt interactions: 0
[2020.07.16-13.19.30:911][290]Cmd: MAP CHECK NOTIFYRESULTS
[2020.07.16-13.19.30:911][290]MapCheck: New page: 1_Main - 16 Jul 2020, 15:19:30

I’ve just tested building geometry only and it crashes instantly with the following message:

Assertion failed: Actor->Brush->RootOutside [File:D:/Build/++UE4+Licensee/Sync/Engine/Source/Editor/UnrealEd/Private/BSPOps.cpp] [Line: 527]

Ok so I found the issue. Somehow I had managed to add a navmeshboundsvolume to a Prefab (using the Prefabricator plugin). I think then that clashed with another navmesh when I duplicated the Prefab.