Heres the log file:
MachineId:
EpicAccountId:
Unknown exception - code 00000001 (first/second chance not available)
"Assertion failed: &Swarm != NULL [File:D:\BuildFarm\buildmachine_++depot+UE4-Releases+4.10\Engine\Source\Editor\UnrealEd\Private\Lightmass\Lightmass.cpp] [Line: 2288]
"
UE4Editor_Core!FDebug::AssertFailed() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\core\private\misc\outputdevice.cpp:374]
UE4Editor_UnrealEd!FLightmassProcessor::FLightmassProcessor() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\editor\unrealed\private\lightmass\lightmass.cpp:2288]
UE4Editor_UnrealEd!FStaticLightingSystem::CreateLightmassProcessor() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\editor\unrealed\private\staticlightingsystem\staticlightingsystem.cpp:1704]
UE4Editor_UnrealEd!FStaticLightingSystem::BeginLightmassProcess() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\editor\unrealed\private\staticlightingsystem\staticlightingsystem.cpp:576]
UE4Editor_UnrealEd!FStaticLightingManager::CreateStaticLightingSystem() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\editor\unrealed\private\staticlightingsystem\staticlightingsystem.cpp:219]
UE4Editor_UnrealEd!UEditorEngine::BuildLighting() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\editor\unrealed\private\staticlightingsystem\staticlightingsystem.cpp:2153]
UE4Editor_UnrealEd!FEditorBuildUtils::EditorBuild() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\editor\unrealed\private\editorbuildutils.cpp:283]
UE4Editor_LevelEditor!TBaseStaticDelegateInstance::ExecuteIfSafe() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\core\public\delegates\delegateinstancesimpl_variadics.inl:921]
UE4Editor_Slate!FUICommandList::ExecuteAction() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\slate\private\framework\commands\uicommandlist.cpp:87]
UE4Editor_Slate!SMenuEntryBlock::OnClicked() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\slate\private\framework\multibox\smenuentryblock.cpp:967]
UE4Editor_Slate!SMenuEntryBlock::OnMenuItemButtonClicked() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\slate\private\framework\multibox\smenuentryblock.cpp:927]
UE4Editor_Slate!TMemberFunctionCaller::operator()<>() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\core\public\delegates\delegateinstanceinterface_variadics.h:161]
UE4Editor_Slate!TTupleImpl >::ApplyAfter_ExplicitReturnType >() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\core\public\delegates\tuple.h:113]
UE4Editor_Slate!TBaseSPMethodDelegateInstance<0,SMenuEntryBlock,0,FReply cdecl(void)>::Execute() [d:\buildfarm\buildmachine++depot+ue4-releases+4.10\engine\source\runtime\core\public\delegates\delegateinstancesimpl_variadics.inl:282]
UE4Editor_Slate!TBaseDelegate::Execute() [d:\buildfarm\buildmachine++depot+ue4-releases+4.10\engine\source\runtime\core\public\delegates\delegatesignatureimpl_variadics.inl:440]
UE4Editor_Slate!SButton::OnMouseButtonUp() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\slate\private\widgets\input\sbutton.cpp:236]
UE4Editor_Slate!SMenuEntryButton::OnMouseButtonUp() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\slate\private\framework\multibox\smenuentryblock.cpp:361]
UE4Editor_Slate!::operator()() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:4276]
UE4Editor_Slate!FEventRouter::Route >() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:214]
UE4Editor_Slate!FSlateApplication::RoutePointerUpEvent() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:4266]
UE4Editor_Slate!FSlateApplication::ProcessMouseButtonUpEvent() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:4663]
UE4Editor_Slate!FSlateApplication::OnMouseUp() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:4641]
UE4Editor_Core!FWindowsApplication::ProcessDeferredMessage() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\core\private\windows\windowsapplication.cpp:1416]
UE4Editor_Core!FWindowsApplication::DeferMessage() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\core\private\windows\windowsapplication.cpp:1721]
UE4Editor_Core!FWindowsApplication::ProcessMessage() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\core\private\windows\windowsapplication.cpp:719]
UE4Editor_Core!FWindowsApplication::AppWndProc() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\core\private\windows\windowsapplication.cpp:641]
user32
user32
UE4Editor_Core!FWindowsPlatformMisc::PumpMessages() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\core\private\windows\windowsplatformmisc.cpp:884]
UE4Editor!FEngineLoop::Tick() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\launch\private\launchengineloop.cpp:2391]
UE4Editor!GuardedMain() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\launch\private\launch.cpp:142]
UE4Editor!GuardedMainWrapper() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\launch\private\windows\launchwindows.cpp:126]
UE4Editor!WinMain() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\launch\private\windows\launchwindows.cpp:200]
UE4Editor!__scrt_common_main_seh() [f:\dd\vctools\crt\vcstartup\src\startup\exe_common.inl:264]
kernel32
ntdll