4.10 build crashes unreal instantly at swarm connection message

4.10 build crashes unreal instantly at swarm connection message. OR sometimes it just said lighting build failed…

Here is the log in unreal editor…

LightingResults: New page: Lighting Build
LoadErrors: New page: Loading map: BathHouse_Sections3.umap
MapCheck: New page: Map Check
LightingResults: New page: Lighting Build
LogParticles: Destroying 0 GPU particle simulations for FXSystem 0x000000FB689C6DE0
LogEditorServer: Finished looking for orphan Actors (0.000 secs)
Cmd: MAP CHECKDEP NOCLEARLOG
MapCheck: Info Map check complete: 0 Error(s), 0 Warning(s), took 381.238ms to complete.
LogFileHelpers: Loading map ‘BathHouse_Sections3’ took 1.816
Cmd: UpdateLandscapeEditorData -warnings
Cmd: UpdateLandscapeEditorData
LogHttp:Warning: Timeout processing Http request. 000000FC87E6C200
MapCheck: New page: Map Check
Cmd: MAP REBUILD ALLVISIBLE
LogEditorServer: Rebuildmap Clear paths rebuilt
MapCheck:Warning: Warning WorldSettings_1 Hierarchical LOD System is disabled or no HLOD level settings available, unable to build LOD actors.
LogStats: STAT_HLOD_BuildClusters - 45.661 ms
LightingResults: New page: Lighting Build - Nov 15, 2015, 11:04:59 AM
LightingResults:Warning: Warning InstancedFoliageActor_1 Instanced meshes don’t yet support unique static lighting for each LOD, lighting on LOD 1+ may be incorrect
LightingResults:Warning: Warning InstancedFoliageActor_1 Instanced meshes don’t yet support unique static lighting for each LOD, lighting on LOD 1+ may be incorrect
LightingResults:Warning: Warning InstancedFoliageActor_1 Instanced meshes don’t yet support unique static lighting for each LOD, lighting on LOD 1+ may be incorrect
LightingResults:Warning: Warning InstancedFoliageActor_1 Instanced meshes don’t yet support unique static lighting for each LOD, lighting on LOD 1+ may be incorrect
LightingResults:Warning: Warning InstancedFoliageActor_1 Instanced meshes don’t yet support unique static lighting for each LOD, lighting on LOD 1+ may be incorrect
LightingResults:Warning: Warning InstancedFoliageActor_1 Instanced meshes don’t yet support unique static lighting for each LOD, lighting on LOD 1+ may be incorrect
LightingResults:Warning: Warning InstancedFoliageActor_1 Instanced meshes don’t yet support unique static lighting for each LOD, lighting on LOD 1+ may be incorrect
LightingResults:Warning: Warning InstancedFoliageActor_1 Instanced meshes don’t yet support unique static lighting for each LOD, lighting on LOD 1+ may be incorrect
LightingResults:Warning: Warning InstancedFoliageActor_1 Instanced meshes don’t yet support unique static lighting for each LOD, lighting on LOD 1+ may be incorrect
LightingResults:Warning: Warning InstancedFoliageActor_1 Instanced meshes don’t yet support unique static lighting for each LOD, lighting on LOD 1+ may be incorrect
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 0:00:02
Cmd: UpdateLandscapeEditorData