Lightmass crashed: ===Unhandled Exception: EXCEPTION_INT_DIVIDE_BY_ZERO

Hi,

I’m doing archviz and getting this error when trying to bake my scene.
It also happens on older scenes that workded smoothly before…
I already tried to make a verification of UE 4.23 and did the clean & validate trick on the swarm agent.
My setup is an I7-7700 with 32Go of RAM.

Thanks for your help

=== Lightmass crashed: ===Unhandled Exception: EXCEPTION_INT_DIVIDE_BY_ZERO
Fatal error: [File:D:/Build/++UE4/Sync/Engine/Source/Programs/UnrealLightmass/Private/Lighting/LightingSystem.cpp] [Line: 1352]
Static lighting thread exception:
Unhandled Exception: EXCEPTION_INT_DIVIDE_BY_ZERO

0x000000013fc39a7b UnrealLightmass.exe!Lightmass::FStaticLightingSystem::IncomingRadianceAdaptive >() []
0x000000013fc4c81f UnrealLightmass.exe!Lightmass::FStaticLightingSystem::CachePointIncomingRadiance() []
0x000000013fced8ee UnrealLightmass.exe!Lightmass::FStaticLightingSystem::ProcessCacheIndirectLightingTask() []
0x000000013fce3a2d UnrealLightmass.exe!Lightmass::FStaticLightingSystem::CalculateIndirectLightingTextureMapping() []
0x000000013fcf024b UnrealLightmass.exe!Lightmass::FStaticLightingSystem::ProcessTextureMapping() []
0x000000013fcd6a45 UnrealLightmass.exe!Lightmass::FStaticLightingSystem::ThreadLoop() []
0x000000013fcd1d0e UnrealLightmass.exe!Lightmass::FMappingProcessingThreadRunnable::Run() []
0x000007fe9b66c4eb UnrealLightmass-Core.dll!UnknownFunction []
0x000007fe9b6637e1 UnrealLightmass-Core.dll!UnknownFunction []
0x00000000779c59cd kernel32.dll!UnknownFunction []
0x0000000077afa561 ntdll.dll!UnknownFunction []

You can try “Clean” on the cache of Swarm. Sometimes it can fix problems.

Thanks for your tip but as mentioned i already tried and it didn’t worked…

Sorry for bumping in to old thread.
Did you find any solution?
I’m running 4.25 and have same issue.
Cleaning and validating cache of swarm obviously didn’t solve.
Blowing up the intermediate and derived data cache folder also didn’t help.

Hello,

As i can remember i didn’t find any solution for this problem.
I had to move my project to another version to continue my work…

Good luck

Took the starting scene in 4.25.3 with the ArchVis setting. No raytracing support.

Build lighting. Remove floor. Build lighting. Lightmass crashes.

Hey folks,

Nothing like a nice forum answer 2 years after the fact, but I was having the same issue. No answers anywhere, and no way to contact any kind of real Unreal support, so I had no choice but to keep clicking through the endless menus and drop downs in unreal until I came across something kind of obvious.

Under World settings, Lightmass, I saw that there was one of those yellow arrows indicating that something had been changed from the default and could be changed back (brilliant feature!) I clicked on that arrow next to ‘lightmass settings’ resetting that to default, then did a lighting build. No problem. NO more Divide by Zero error. No failure. I hope this helps you or anyone else who comes across this.

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Hi, I found a partial solution, the issue is caused by one asset placed in your scene (not in content), In my case I delete those level recently placed assets , one by one until the build works fine again.

It was the same for me. I did what you said and I solved it. Thanks