Build Lighting stuck forever even with new project on a clean system

Hello.

It’s kinda strange - I can’t building lighting after I updated to 4.9.0. I even bought new ssd and installed a new OS (Windows 10 x64) on it but building does not work:

  1. Create new project
  2. Create blank level in it
  3. Add Cube to level
  4. Add Point Light to level
  5. Choose build lightning only

Result:

12:42:24 AM: Starting up SwarmAgent ...
12:42:24 AM:  ... registering SwarmAgent with remoting service
12:42:24 AM:  ... registering SwarmAgent network channels
12:42:24 AM:  ... initializing SwarmAgent
12:42:24 AM:  ......... certificate check has failed
12:42:24 AM:  ...... initializing cache
12:42:24 AM:  ......... using cache folder 'C:/Users/norma/AppData/Local/UnrealEngine/4.9/Saved/Swarm\SwarmCache'
12:42:24 AM:  ......... recreating SwarmAgent cache staging area
12:42:24 AM:  ...... initializing connection to SwarmCoordinator
12:42:24 AM:  ......... using SwarmCoordinator on RENDER-01
12:42:26 AM:  ......... SwarmCoordinator failed to be initialized
12:42:26 AM:  ...... initializing local performance monitoring subsystem
12:42:26 AM:  ... initialization successful, SwarmAgent now running
12:42:26 AM: [Interface:TryOpenConnection] Local connection established
12:42:26 AM: [Job] Accepted Job 7FA5937E-438AE7BE-B7979798-56A405D3
12:42:26 AM: [Job] Launched Job UnrealLightmass_2015-09-07_19-55-33_1325512-64bit.exe
12:42:26 AM: [Job]     PID is 3520
12:42:26 AM: [Job]     GUID is "7FA5937E-438AE7BE-B7979798-56A405D3"
12:42:27 AM: LogLightmass:Display: Lightmass Win64 started on: DESKTOP-AK8K7K3. Command-line: 7FA5937E438AE7BEB797979856A405D3
12:42:27 AM: Lightmass Win64 started on: DESKTOP-AK8K7K3. Command-line: 7FA5937E438AE7BEB797979856A405D3
12:42:27 AM: LogLightmass:Display: Processing scene GUID: 7FA5937E438AE7BEB797979856A405D3 with 3 threads
12:42:27 AM: Processing scene GUID: 7FA5937E438AE7BEB797979856A405D3 with 3 threads
12:42:27 AM: Building static lighting...
12:42:27 AM: LogGenericPlatformMisc:Warning: Failed to determine engine directory: Defaulting to ../../../Engine/
12:42:27 AM: Failed to determine engine directory: Defaulting to ../../../Engine/
12:42:27 AM: [Job] Found a parent connection for PID 3520
12:42:27 AM: [Job]     0529195B -> 504CAD99
12:42:27 AM: [Interface:TryOpenConnection] Local connection established
12:42:27 AM: Measured CPU frequency: 3.29 GHz
12:42:27 AM: FStaticLightingSystem started using GKDOPMaxTrisPerLeaf: 4
12:42:27 AM: Number of texture mappings: 1
12:42:27 AM: Number of fluid mappings:   0
12:42:27 AM: Number of landscape mappings:   0
12:42:27 AM: Number of BSP mappings:     0
12:42:27 AM: Number of static mesh instance mappings: 1
12:42:27 AM: Reserving memory for 1 meshes, 54 vertices, 48 triangles
12:42:27 AM: Scene surface area calculated at 0.060 million units (52.613% of the estimated 0.114 million units)
12:42:27 AM: Importance volume surface area calculated at 0.060 million units (0.000% of the estimated 0.000 million units)
12:42:27 AM: Preallocated 0.0Gb for kDOP nodes and triangles
12:42:27 AM: Building kDOP took  0.00 seconds.
12:42:27 AM: Static lighting kDOP: 30 nodes, 16 leaves, 64 triangles, 54 vertices
12:42:27 AM: Static lighting kDOP: 25.000% wasted space in leaves
12:42:27 AM: kDopTree.Nodes        :     0.0Mb
12:42:27 AM: kDopTree.SOATriangles :     0.0Mb
12:42:27 AM: kDOPTriangles         :     0.0Mb
12:42:27 AM: TrianglePayloads      :     0.0Mb
12:42:27 AM: MeshInfos             :     0.0Mb
12:42:27 AM: Vertices              :     0.0Mb
12:42:27 AM: UVs                   :     0.0Mb
12:42:27 AM: LightmapUVs           :     0.0Mb
12:42:27 AM: Static lighting kDOP: 30 nodes, 16 leaves, 64 triangles, 54 vertices, 0.0 Mb
12:42:27 AM: Processing...
12:42:27 AM: EmitDirectPhotons complete, 0.004 million photons emitted in 0.0 seconds
12:42:27 AM: EmitIndirectPhotons complete, 0.000 million photons emitted in 0.0 seconds
12:42:27 AM: Marking Irradiance Photons complete, 0.000 million photons marked in 0.0 seconds
12:42:27 AM: Caching Irradiance Photons complete, 0.000 million cache samples in 0.0 seconds
12:42:27 AM: Calculate Irradiance Photons complete, 0.000 million irradiance calculations in 0.0 seconds
12:42:27 AM: Lighting 100.0%

It stuck on 100% and hanged forever. Sometimes on Win 8.1 x64 I was able to build lighting. 2 times of ~50… I don’t know how I did it - just luck.

My system spec is:

  • Intel(R) Core™ i5-4590 CPU @
    3.30GHz
  • 8.00GB RAM
  • Palit GeForce GTX 750 StormX OC 1024MB GDDR5 (NE5X750S1301-1073F)

May changing video card can help? What do you recommend?

Update: after I created LightmassImportanceVolume in new blank level and changed it scale to 10x10x10 the lighting has successfully builded.

I don´t know why but this worked for me too! o.O

tks!!

This is currently a known issue reported with UE-20782. We don’t have a fix yet, but it has been assigned for investigation. Hopefully we’ll have a resolution soon.