We are moving our project from 4.14.3 to 4.18.3 (git source), everything works as intended in the editor however whenever we try to build lighting, when we try to build lighting we get the following issue on the swarm agent:
11:29:00 PM: [Interface:EndJobSpecification] Error: Index was out of range. Must be non-negative and less than the size of the collection.
Parameter name: index System.ArgumentOutOfRangeException: Index was out of range. Must be non-negative and less than the size of the collection.
Parameter name: index
Server stack trace:
at System.ThrowHelper.ThrowArgumentOutOfRangeException(ExceptionArgument argument, ExceptionResource resource)
at Agent.AgentJob.EndJobSpecification()
at Agent.Agent.EndJobSpecification_1_0(Int32 ConnectionHandle, Hashtable InParameters, Hashtable& OutParameters)
at System.Runtime.Remoting.Messaging.StackBuilderSink._PrivateProcessMessage(IntPtr md, Object[] args, Object server, Object[]& outArgs)
at System.Runtime.Remoting.Messaging.StackBuilderSink.SyncProcessMessage(IMessage msg)
Exception rethrown at [0]:
at System.Runtime.Remoting.Proxies.RealProxy.HandleReturnMessage(IMessage reqMsg, IMessage retMsg)
at System.Runtime.Remoting.Proxies.RealProxy.PrivateInvoke(MessageData& msgData, Int32 type)
at NSwarm.IAgentInterfaceWrapper.EndJobSpecificationDelegate.EndInvoke(Hashtable& OutParameters, IAsyncResult result)
at NSwarm.IAgentInterfaceWrapper.EndJobSpecification(Int32 ConnectionHandle)
at NSwarm.FSwarmInterface.EndJobSpecification()
I found another thread which suggested trying earlier versions of the swarm agent, so we tried with the 4.14 version which lighting appeared to build successfully up until the point of the editor attempting to import the new build data which gave the following fatal crash to the engine:
LoginId:20ae57204a0c08f908de31ac07b6f900
EpicAccountId:46a586683b6441709f70fcc2d91c19a2
Fatal error: [File:X:\UE4.18\Engine\Source\Runtime\Core\Private\GenericPlatform\GenericPlatformMemory.cpp] [Line: 183] Ran out of memory allocating 18446744073511354368 bytes with alignment 0
UE4Editor_Core!FDebug::AssertFailed() [x:\ue4.18\engine\source\runtime\core\private\misc\assertionmacros.cpp:414]
UE4Editor_Core!FGenericPlatformMemory::OnOutOfMemory() [x:\ue4.18\engine\source\runtime\core\private\genericplatform\genericplatformmemory.cpp:184]
UE4Editor_Core!FMallocTBB::Realloc() [x:\ue4.18\engine\source\runtime\core\private\hal\malloctbb.cpp:120]
UE4Editor_Core!FMemory::Realloc() [x:\ue4.18\engine\source\runtime\core\public\hal\fmemory.inl:48]
UE4Editor_UnrealEd!TArray::ResizeTo() [x:\ue4.18\engine\source\runtime\core\public\containers\array.h:2265]
UE4Editor_UnrealEd!FLightmassProcessor::ImportVolumetricLightmap() [x:\ue4.18\engine\source\editor\unrealed\private\lightmass\importvolumetriclightmap.cpp:906]
UE4Editor_UnrealEd!FLightmassProcessor::CompleteRun() [x:\ue4.18\engine\source\editor\unrealed\private\lightmass\lightmass.cpp:3113]
UE4Editor_UnrealEd!FStaticLightingSystem::FinishLightmassProcess() [x:\ue4.18\engine\source\editor\unrealed\private\staticlightingsystem\staticlightingsystem.cpp:2086]
UE4Editor_UnrealEd!FStaticLightingManager::ProcessLightingData() [x:\ue4.18\engine\source\editor\unrealed\private\staticlightingsystem\staticlightingsystem.cpp:164]
UE4Editor_UnrealEd!FStaticLightingSystem::UpdateLightingBuild() [x:\ue4.18\engine\source\editor\unrealed\private\staticlightingsystem\staticlightingsystem.cpp:2230]
UE4Editor_UnrealEd!FStaticLightingManager::UpdateBuildLighting() [x:\ue4.18\engine\source\editor\unrealed\private\staticlightingsystem\staticlightingsystem.cpp:327]
UE4Editor_UnrealEd!UEditorEngine::UpdateBuildLighting() [x:\ue4.18\engine\source\editor\unrealed\private\staticlightingsystem\staticlightingsystem.cpp:2312]
UE4Editor!FEngineLoop::Tick() [x:\ue4.18\engine\source\runtime\launch\private\launchengineloop.cpp:3296]
UE4Editor!GuardedMain() [x:\ue4.18\engine\source\runtime\launch\private\launch.cpp:166]
UE4Editor!GuardedMainWrapper() [x:\ue4.18\engine\source\runtime\launch\private\windows\launchwindows.cpp:134]
UE4Editor!WinMain() [x:\ue4.18\engine\source\runtime\launch\private\windows\launchwindows.cpp:210]
UE4Editor!__scrt_common_main_seh() [f:\dd\vctools\crt\vcstartup\src\startup\exe_common.inl:253]
kernel32
ntdll
There is absolutely no way computing lighting can attempt to use 18446744tb of data, what are we supposed to do in this instance? This worked perfectly fine in 4.14.3, in 4.18.3 it seems we just can’t build any lighting, no map that exists in our project packages successfully however creating an empty project and packaging an empty map from there works just fine. Our project is too large of a scale to easily say “oh just try deleting a couple of assets” but with how many reports of swarm/lighting failing to work in 4.18 there must be some underlying issue.