# Lightmass crashed

**URL:** <https://forums.unrealengine.com/t/lightmass-crashed/133526>\
**Category:** Rendering\
**Tags:** unreal-engine\
**Created:** [November 15, 2019, 8:56am UTC](https://forums.unrealengine.com/t/lightmass-crashed/133526 "2019-11-15T08:56:49Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![R4ko0n](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@R4ko0n](https://forums.unrealengine.com/u/R4ko0n)\
**Post date:** [November 15, 2019, 8:56am UTC](https://forums.unrealengine.com/t/lightmass-crashed/133526/1 "2019-11-15T08:56:49Z")

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Hi there,

can anyone point me to the right direction?

\<None\> === Lightmass crashed: ===  
Assertion failed: (Index \>= 0) & (Index \< ArrayNum) [File:d:\build++ue4\sync\engine\source\runtime\core\public\Containers/Array.h] [Line: 614]  
Array index out of bounds: 28730 from an array of size 28730

0x00007ff911aea839 KERNELBASE.dll!UnknownFunction ]  
0x00007ff838b2faa7 UnrealLightmass-Core.dll!UnknownFunction ]  
0x00007ff838b324b1 UnrealLightmass-Core.dll!UnknownFunction ]  
0x00007ff8389bb22a UnrealLightmass-Core.dll!UnknownFunction ]  
0x00007ff83891ce87 UnrealLightmass-Core.dll!UnknownFunction ]  
0x00007ff83891d540 UnrealLightmass-Core.dll!UnknownFunction ]  
0x00007ff7bf099148 UnrealLightmass.exe!DispatchCheckVerify\<void,\<lambda\_6baa7e18da244a9bdc419e5917d5de41\> \>() ]  
0x00007ff7befde7a6 UnrealLightmass.exe!Lightmass::FEmbreeGeometry::FEmbreeGeometry() ]  
0x00007ff7befe6f93 UnrealLightmass.exe!Lightmass::FEmbreeAggregateMesh::AddMesh() ]  
0x00007ff7bf0342b4 UnrealLightmass.exe!Lightmass::FStaticLightingSystem::FStaticLightingSystem() ]  
0x00007ff7befeab54 UnrealLightmass.exe!Lightmass::BuildStaticLighting() ]  
0x00007ff7bf00e11d UnrealLightmass.exe!Lightmass::LightmassMain() ]  
0x00007ff7bf02cb1a UnrealLightmass.exe!main() ]  
0x00007ff7bf095cfc UnrealLightmass.exe!\_\_scrt\_common\_main\_seh() ]  
0x00007ff9134e7bd4 KERNEL32.DLL!UnknownFunction ]  
0x00007ff913eeced1 ntdll.dll!UnknownFunction ]

Kind regards

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<div class="post-metadata">

**Author:** ![anonymous\_user\_f26c856c1](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@anonymous\_user\_f26c856c1](https://forums.unrealengine.com/u/anonymous_user_f26c856c1)\
**Post date:** [November 15, 2019, 8:14pm UTC](https://forums.unrealengine.com/t/lightmass-crashed/133526/2 "2019-11-15T20:14:07Z")

</div>

Hi!

Maybe you’ll just need to clean and then validate your swarm agent cache!

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