Duplicating Level With Large _BuiltData File Results in Editor Crash

Trying to duplicate a level in the editor that has a large _BuiltData file results in a crash. In the case of the supplied test level, it is over 3 GB. Crash repros in 4.19.2 and Main (CL 4115885).

Per User:

For me works this solution: hiding the _BuiltData.uasset file of the level and then run the UE4 editor, create a duplicate ( now duplication works fine w/o this large asset file ), exit UE4 editor, unhide the _BuiltData.uasset file and run editor again. Ofcourse you do not have any _BuiltData.uasset for the new duplicate of the level. But the source level stay untouched.

1. Open sample project (download from [Link Removed] )
2. Go to Content > Maps folder
3. Right-Click, Duplicate Spalice-SUNNYDAY level

Result: Crash

Expected: Level will be duplicated

Assertion failed: (Index >= 0) & (Index < ArrayNum) [Link Removed] [Line: 610] Array index out of bounds: 2080663101 from an array of size -2147195347

UE4Editor_Core!FDebug::AssertFailed() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\core\private\misc\assertionmacros.cpp:419]
UE4Editor_CoreUObject!FDuplicateDataWriter::Serialize() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\coreuobject\public\serialization\duplicateddatawriter.h:52]
UE4Editor_Engine!operator<<() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\core\public\containers\array.h:1120]
UE4Editor_Engine!operator<<() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\engine\private\mapbuilddata.cpp:294]
UE4Editor_Engine!operator<<() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\core\public\containers\sparsearray.h:487]
UE4Editor_Engine!operator<<() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\core\public\containers\set.h:742]
UE4Editor_Engine!UMapBuildDataRegistry::Serialize() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\engine\private\mapbuilddata.cpp:376]
UE4Editor_CoreUObject!StaticDuplicateObjectEx() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\coreuobject\private\uobject\uobjectglobals.cpp:2054]
UE4Editor_CoreUObject!StaticDuplicateObject() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\coreuobject\private\uobject\uobjectglobals.cpp:1960]
UE4Editor_Engine!UWorld::PostDuplicate() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\engine\private\world.cpp:668]
UE4Editor_CoreUObject!StaticDuplicateObjectEx() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\coreuobject\private\uobject\uobjectglobals.cpp:2103]
UE4Editor_CoreUObject!StaticDuplicateObject() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\coreuobject\private\uobject\uobjectglobals.cpp:1960]
UE4Editor_UnrealEd!ObjectTools::DuplicateSingleObject() [d:\build\++ue4+release-4.19+compile\sync\engine\source\editor\unrealed\private\objecttools.cpp:520]
UE4Editor_AssetTools!UAssetToolsImpl::PerformDuplicateAsset() [d:\build\++ue4+release-4.19+compile\sync\engine\source\developer\assettools\private\assettools.cpp:590]
UE4Editor_AssetTools!UAssetToolsImpl::DuplicateAsset() [d:\build\++ue4+release-4.19+compile\sync\engine\source\developer\assettools\private\assettools.cpp:564]
UE4Editor_ContentBrowser!SAssetView::CreateAssetFromTemporary() [d:\build\++ue4+release-4.19+compile\sync\engine\source\editor\contentbrowser\private\sassetview.cpp:3647]
UE4Editor_ContentBrowser!SAssetView::AssetRenameCommit() [d:\build\++ue4+release-4.19+compile\sync\engine\source\editor\contentbrowser\private\sassetview.cpp:4088]
UE4Editor_ContentBrowser!TBaseSPMethodDelegateInstance<0,SAssetView,0,TTypeWrapper<void> __cdecl(TSharedPtr<FAssetViewItem,0> const & __ptr64,FString const & __ptr64,FSlateRect const & __ptr64,enum ETextCommit::Type)>::Execute() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\core\public\delegates\delegateinstancesimpl.h:269]
UE4Editor_ContentBrowser!TBaseSPMethodDelegateInstance<0,SAssetView,0,void __cdecl(TSharedPtr<FAssetViewItem,0> const & __ptr64,FString const & __ptr64,FSlateRect const & __ptr64,enum ETextCommit::Type)>::ExecuteIfSafe() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\core\public\delegates\delegateinstancesimpl.h:345]
UE4Editor_ContentBrowser!SAssetViewItem::HandleNameCommitted() [d:\build\++ue4+release-4.19+compile\sync\engine\source\editor\contentbrowser\private\assetviewwidgets.cpp:554]
UE4Editor_ContentBrowser!TBaseSPMethodDelegateInstance<0,SAssetTileItem,0,TTypeWrapper<void> __cdecl(FText const & __ptr64,enum ETextCommit::Type)>::Execute() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\core\public\delegates\delegateinstancesimpl.h:269]
UE4Editor_ContentBrowser!TBaseSPMethodDelegateInstance<0,SAssetTileItem,0,void __cdecl(FText const & __ptr64,enum ETextCommit::Type)>::ExecuteIfSafe() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\core\public\delegates\delegateinstancesimpl.h:345]
UE4Editor_Slate!SInlineEditableTextBlock::OnTextBoxCommitted() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\slate\private\widgets\text\sinlineeditabletextblock.cpp:312]
UE4Editor_Slate!TBaseSPMethodDelegateInstance<0,SInlineEditableTextBlock,0,TTypeWrapper<void> __cdecl(FText const & __ptr64,enum ETextCommit::Type)>::Execute() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\core\public\delegates\delegateinstancesimpl.h:269]
UE4Editor_Slate!TBaseSPMethodDelegateInstance<0,SInlineEditableTextBlock,0,void __cdecl(FText const & __ptr64,enum ETextCommit::Type)>::ExecuteIfSafe() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\core\public\delegates\delegateinstancesimpl.h:345]
UE4Editor_Slate!FSlateEditableTextLayout::HandleFocusLost() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\slate\private\widgets\text\slateeditabletextlayout.cpp:783]
UE4Editor_Slate!FSlateApplication::SetUserFocus() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:2893]
UE4Editor_Slate!FSlateApplication::SetUserFocus() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:2595]
UE4Editor_Slate!FSlateApplication::ProcessReply() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:3325]
UE4Editor_Slate!FEventRouter::Route<FReply,FEventRouter::FBubblePolicy,FPointerEvent,<lambda_7097b900f0e4be30d80fb18f98c51ea0> >() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:267]
UE4Editor_Slate!FSlateApplication::RoutePointerDownEvent() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:5337]
UE4Editor_Slate!FSlateApplication::ProcessMouseButtonDownEvent() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:5290]
UE4Editor_Slate!FSlateApplication::OnMouseDown() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:5208]
UE4Editor_ApplicationCore!FWindowsApplication::ProcessDeferredMessage() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\applicationcore\private\windows\windowsapplication.cpp:1734]
UE4Editor_ApplicationCore!FWindowsApplication::DeferMessage() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\applicationcore\private\windows\windowsapplication.cpp:2172]
UE4Editor_ApplicationCore!FWindowsApplication::ProcessMessage() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\applicationcore\private\windows\windowsapplication.cpp:889]
UE4Editor_ApplicationCore!FWindowsApplication::AppWndProc() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\applicationcore\private\windows\windowsapplication.cpp:726]
user32
user32
UE4Editor_ApplicationCore!FWindowsPlatformApplicationMisc::PumpMessages() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\applicationcore\private\windows\windowsplatformapplicationmisc.cpp:129]
UE4Editor!FEngineLoop::Tick() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\launch\private\launchengineloop.cpp:3263]
UE4Editor!GuardedMain() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\launch\private\launch.cpp:166]
UE4Editor!GuardedMainWrapper() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\launch\private\windows\launchwindows.cpp:144]
UE4Editor!WinMain() [d:\build\++ue4+release-4.19+compile\sync\engine\source\runtime\launch\private\windows\launchwindows.cpp:223]
UE4Editor!__scrt_common_main_seh() [f:\dd\vctools\crt\vcstartup\src\startup\exe_common.inl:253]
kernel32
ntdll