Error when Building Lighting

I keep getting this error when I try to build the lights in my scene;

Access violation - code c0000005 (first/second chance not available)

UE4Editor_UnrealEd!TSet,TDefaultMapKeyFuncs,FDefaultSetAllocator>::Emplace >() [d:\build++ue4+release-4.13+compile\sync\engine\source\runtime\core\public\containers\set.h:484]
UE4Editor_UnrealEd!UEditorEngine::Map_Check() [d:\build++ue4+release-4.13+compile\sync\engine\source\editor\unrealed\private\editorserver.cpp:3816]
UE4Editor_UnrealEd!UEditorEngine::HandleMapCommand() [d:\build++ue4+release-4.13+compile\sync\engine\source\editor\unrealed\private\editorserver.cpp:5991]
UE4Editor_UnrealEd!UEditorEngine::Exec() [d:\build++ue4+release-4.13+compile\sync\engine\source\editor\unrealed\private\editorserver.cpp:5479]
UE4Editor_UnrealEd!UUnrealEdEngine::Exec() [d:\build++ue4+release-4.13+compile\sync\engine\source\editor\unrealed\private\unrealedsrv.cpp:624]
UE4Editor_Engine!UEngine::TickDeferredCommands() [d:\build++ue4+release-4.13+compile\sync\engine\source\runtime\engine\private\unrealengine.cpp:1111]
UE4Editor!FEngineLoop::Tick() [d:\build++ue4+release-4.13+compile\sync\engine\source\runtime\launch\private\launchengineloop.cpp:2940]
UE4Editor!GuardedMain() [d:\build++ue4+release-4.13+compile\sync\engine\source\runtime\launch\private\launch.cpp:156]
UE4Editor!GuardedMainWrapper() [d:\build++ue4+release-4.13+compile\sync\engine\source\runtime\launch\private\windows\launchwindows.cpp:126]
UE4Editor!WinMain() [d:\build++ue4+release-4.13+compile\sync\engine\source\runtime\launch\private\windows\launchwindows.cpp:202]
UE4Editor!__scrt_common_main_seh() [f:\dd\vctools\crt\vcstartup\src\startup\exe_common.inl:264]
kernel32
ntdll

Any help would be gratefully received.

-J-

Hi Janek,

Can you provide the full log from the project along with the machine/Epic ID that happens when you get the crash reporter? Without the full log or the IDs this isn’t necessarily enough to go on by itself.

If you can also grab a super verbose log from Swarm Agent as well that would be helpful.

Also, is this only happening in your project or happening in a new blank project as well?

Thank you!

Tim