Nanite Landscape Visibility Layer Crash

Upon saving the level after creating the landscape and painting visibility, the editor crashes. When you restart the editor and load the level, you are greeted with a warning in the upper right corner of the viewport and a map check error that prompts you to rebuild that Nanite landscape. Upon rebuilding, the warning persists. If you then try to cook the level, the cooker crashes. Attempting to clear the visibility data using the landscape tool does not resolve the issue and upon clearing, if you then attempt to Save, the editor crashes with the attached stack trace.

The attached project has one level, NewMap, that has a landscape that is stuck in this state. If you attempt to cook, you should reproduce the crash.

When rebuilding the landscape, the following appears in the output log:

In UE 5.7:

LogLandscape: Warning: [NaniteDiag] ExportToRawMeshDataCopy produced 0 polygons for actor 'Landscape' (LOD=0, 64 components, polygons=0, 0 w/empty height, 64 w/visibility-paint, 64 w/visibility-data, 0 w/missing component-data, 262144 total height samples, 262144 total visibility samples, 262144 hidden visibility samples, 0 visible visibility samples, ExportBoundsSet=0, SkirtDepthSet=0).

LogLandscape: Failed export of raw static mesh for Nanite landscape (64 components) for actor Landscape : (DDC: 1, DDC read: 0 bytes, DDC write: 0 bytes, key: 7A6172126E32F37EE047EB5FEC99CA4692C4D92E, export: 0.030766 seconds)

In UE 5.8 the warnings are different but the Cook still fails. Upon closing the level the Editor crashes.

Steps to Reproduce

Open the NewMap level in the attached project for a Landscape that is already in the buggy state.

1. Create a Landscape with a material that has a Landscape Visibility mask connected to Opacity Blend Mode = Masked
2. Enable Nanite on the Landscape actor
3. In Landscape Mode, select the Sculpt Tool > Visibility
4. Paint the entire Landscape as invisible (in reality, only a single chunk needs to be invisible, but this makes it easier)
5. Save the Level

========= Saving Call Stack ==========

2026.06.08-20.09.47:102][665]LogWindows: Error: === Critical error: ===

[2026.06.08-20.09.47:102][665]LogWindows: Error:

[2026.06.08-20.09.47:102][665]LogWindows: Error: Fatal error: [Link Removed] [Line: 1938]

[2026.06.08-20.09.47:102][665]LogWindows: Error: World Memory Leaks: 1 leaks objects and packages. See The output above.

[2026.06.08-20.09.47:102][665]LogWindows: Error:

[2026.06.08-20.09.47:102][665]LogWindows: Error:

[2026.06.08-20.09.47:102][665]LogWindows: Error: [Callstack] 0x00007fff84b7c95f UnrealEditor-UnrealEd.dll!UEditorEngine::CheckForWorldGCLeaks() [P:\dev\UnrealEngine\Engine\Source\Editor\UnrealEd\Private\EditorServer.cpp:1940]

[2026.06.08-20.09.47:102][665]LogWindows: Error: [Callstack] 0x00007fff84b864a8 UnrealEditor-UnrealEd.dll!UEditorEngine::EditorDestroyWorld() [P:\dev\UnrealEngine\Engine\Source\Editor\UnrealEd\Private\EditorServer.cpp:2073]

[2026.06.08-20.09.47:102][665]LogWindows: Error: [Callstack] 0x00007fff84ba5b52 UnrealEditor-UnrealEd.dll!UEditorEngine::Map_Load() [P:\dev\UnrealEngine\Engine\Source\Editor\UnrealEd\Private\EditorServer.cpp:2464]

[2026.06.08-20.09.47:102][665]LogWindows: Error: [Callstack] 0x00007fff84b94b3d UnrealEditor-UnrealEd.dll!UEditorEngine::HandleMapCommand() [P:\dev\UnrealEngine\Engine\Source\Editor\UnrealEd\Private\EditorServer.cpp:6227]

[2026.06.08-20.09.47:102][665]LogWindows: Error: [Callstack] 0x00007fff84b89c1f UnrealEditor-UnrealEd.dll!UEditorEngine::Exec_Editor() [P:\dev\UnrealEngine\Engine\Source\Editor\UnrealEd\Private\EditorServer.cpp:5688]

[2026.06.08-20.09.47:102][665]LogWindows: Error: [Callstack] 0x00007fff87b4ce36 UnrealEditor-Core.dll!FExec::Exec() [P:\dev\UnrealEngine\Engine\Source\Runtime\Core\Private\Misc\Exec.cpp:18]

[2026.06.08-20.09.47:102][665]LogWindows: Error: [Callstack] 0x00007fff648759af UnrealEditor-Engine.dll!UEngine::Exec() [P:\dev\UnrealEngine\Engine\Source\Runtime\Engine\Private\UnrealEngine.cpp:5213]

[2026.06.08-20.09.47:102][665]LogWindows: Error: [Callstack] 0x00007fff85650c4c UnrealEditor-UnrealEd.dll!UUnrealEdEngine::Exec() [P:\dev\UnrealEngine\Engine\Source\Editor\UnrealEd\Private\UnrealEdSrv.cpp:662]

[2026.06.08-20.09.47:102][665]LogWindows: Error: [Callstack] 0x00007fff84f6cc30 UnrealEditor-UnrealEd.dll!FEditorFileUtils::LoadMap() [P:\dev\UnrealEngine\Engine\Source\Editor\UnrealEd\Private\FileHelpers.cpp:3306]

[2026.06.08-20.09.47:102][665]LogWindows: Error: [Callstack] 0x00007fff89b7bfeb UnrealEditor-LevelEditor.dll!FLevelEditorActionCallbacks::SaveCurrentAs() [P:\dev\UnrealEngine\Engine\Source\Editor\LevelEditor\Private\LevelEditorActions.cpp:504]

[2026.06.08-20.09.47:102][665]LogWindows: Error: [Callstack] 0x00007fff89b28e17 UnrealEditor-LevelEditor.dll!TBaseStaticDelegateInstance::ExecuteIfSafe() [P:\dev\UnrealEngine\Engine\Source\Runtime\Core\Public\Delegates\DelegateInstancesImpl.h:827]

[2026.06.08-20.09.47:102][665]LogWindows: Error: [Callstack] 0x00007fffa661e845 UnrealEditor-Slate.dll!FUIAction::Execute() [P:\dev\UnrealEngine\Engine\Source\Runtime\Slate\Public\Framework\Commands\UIAction.h:139]

[2026.06.08-20.09.47:102][665]LogWindows: Error: [Callstack] 0x00007fffa661e9ce UnrealEditor-Slate.dll!FUICommandList::ExecuteAction() [P:\dev\UnrealEngine\Engine\Source\Runtime\Slate\Private\Framework\Commands\UICommandList.cpp:117]

[2026.06.08-20.09.47:102][665]LogWindows: Error: [Callstack] 0x00007fffa6732fa3 UnrealEditor-Slate.dll!SToolBarButtonBlock::OnClicked() [P:\dev\UnrealEngine\Engine\Source\Runtime\Slate\Private\Framework\MultiBox\SToolBarButtonBlock.cpp:530]

[2026.06.08-20.09.47:102][665]LogWindows: Error: [Callstack] 0x00007fffa671044a UnrealEditor-Slate.dll!TBaseSPMethodDelegateInstance<0,SToolBarButtonBlock,1,FReply __cdecl(void),FDefaultDelegateUserPolicy>::Execute() [P:\dev\UnrealEngine\Engine\Source\Runtime\Core\Public\Delegates\DelegateInstancesImpl.h:308]

[2026.06.08-20.09.47:102][665]LogWindows: Error: [Callstack] 0x00007fffa678967b UnrealEditor-Slate.dll!SButton::ExecuteOnClick() [P:\dev\UnrealEngine\Engine\Source\Runtime\Slate\Private\Widgets\Input\SButton.cpp:574]

[2026.06.08-20.09.47:102][665]LogWindows: Error: [Callstack] 0x00007fffa67a24c6 UnrealEditor-Slate.dll!SButton::OnMouseButtonUp() [P:\dev\UnrealEngine\Engine\Source\Runtime\Slate\Private\Widgets\Input\SButton.cpp:442]

[2026.06.08-20.09.47:102][665]LogWindows: Error: [Callstack] 0x00007fffa655ff19 UnrealEditor-Slate.dll!FEventRouter::Route >() [P:\dev\UnrealEngine\Engine\Source\Runtime\Slate\Private\Framework\Application\SlateApplication.cpp:459]

[2026.06.08-20.09.47:102][665]LogWindows: Error: [Callstack] 0x00007fffa65a9159 UnrealEditor-Slate.dll!FSlateApplication::RoutePointerUpEvent() [P:\dev\UnrealEngine\Engine\Source\Runtime\Slate\Private\Framework\Application\SlateApplication.cpp:5465]

[2026.06.08-20.09.47:102][665]LogWindows: Error: [Callstack] 0x00007fffa659bd1a UnrealEditor-Slate.dll!FSlateApplication::ProcessMouseButtonUpEvent() [P:\dev\UnrealEngine\Engine\Source\Runtime\Slate\Private\Framework\Application\SlateApplication.cpp:6050]

[2026.06.08-20.09.47:102][665]LogWindows: Error: [Callstack] 0x00007fffa65933a9 UnrealEditor-Slate.dll!FSlateApplication::OnMouseUp() [P:\dev\UnrealEngine\Engine\Source\Runtime\Slate\Private\Framework\Application\SlateApplication.cpp:6006]

[2026.06.08-20.09.47:102][665]LogWindows: Error: [Callstack] 0x00007ffffa10ea86 UnrealEditor-ApplicationCore.dll!FWindowsApplication::ProcessDeferredMessage() [P:\dev\UnrealEngine\Engine\Source\Runtime\ApplicationCore\Private\Windows\WindowsApplication.cpp:3423]

[2026.06.08-20.09.47:102][665]LogWindows: Error: [Callstack] 0x00007ffffa0f683a UnrealEditor-ApplicationCore.dll!FWindowsApplication::DeferMessage() [P:\dev\UnrealEngine\Engine\Source\Runtime\ApplicationCore\Private\Windows\WindowsApplication.cpp:4120]

[2026.06.08-20.09.47:102][665]LogWindows: Error: [Callstack] 0x00007ffffa111ecf UnrealEditor-ApplicationCore.dll!FWindowsApplication::ProcessMessage() [P:\dev\UnrealEngine\Engine\Source\Runtime\ApplicationCore\Private\Windows\WindowsApplication.cpp:2355]

[2026.06.08-20.09.47:102][665]LogWindows: Error: [Callstack] 0x00007ffffa0f00e1 UnrealEditor-ApplicationCore.dll!FWindowsApplication::AppWndProc() [P:\dev\UnrealEngine\Engine\Source\Runtime\ApplicationCore\Private\Windows\WindowsApplication.cpp:2148]

[2026.06.08-20.09.47:102][665]LogWindows: Error: [Callstack] 0x00007ff85be08eb8 USER32.dll!UnknownFunction []

[2026.06.08-20.09.47:102][665]LogWindows: Error: [Callstack] 0x00007ff85be08771 USER32.dll!UnknownFunction []

[2026.06.08-20.09.47:102][665]LogWindows: Error: [Callstack] 0x00007ffffa134a19 UnrealEditor-ApplicationCore.dll!FWindowsPlatformApplicationMisc::PumpMessages() [P:\dev\UnrealEngine\Engine\Source\Runtime\ApplicationCore\Private\Windows\WindowsPlatformApplicationMisc.cpp:153]

[2026.06.08-20.09.47:102][665]LogWindows: Error: [Callstack] 0x00007ff7790247d9 UnrealEditor.exe!FEngineLoop::Tick() [P:\dev\UnrealEngine\Engine\Source\Runtime\Launch\Private\LaunchEngineLoop.cpp:5753]

[2026.06.08-20.09.47:102][665]LogWindows: Error: [Callstack] 0x00007ff779040bfe UnrealEditor.exe!GuardedMain() [P:\dev\UnrealEngine\Engine\Source\Runtime\Launch\Private\Launch.cpp:190]

[2026.06.08-20.09.47:102][665]LogWindows: Error: [Callstack] 0x00007ff779040d0a UnrealEditor.exe!GuardedMainWrapper() [P:\dev\UnrealEngine\Engine\Source\Runtime\Launch\Private\Windows\LaunchWindows.cpp:123]

[2026.06.08-20.09.47:102][665]LogWindows: Error: [Callstack] 0x00007ff779044590 UnrealEditor.exe!LaunchWindowsStartup() [P:\dev\UnrealEngine\Engine\Source\Runtime\Launch\Private\Windows\LaunchWindows.cpp:277]

[2026.06.08-20.09.47:102][665]LogWindows: Error: [Callstack] 0x00007ff779055be4 UnrealEditor.exe!WinMain() [P:\dev\UnrealEngine\Engine\Source\Runtime\Launch\Private\Windows\LaunchWindows.cpp:334]

[2026.06.08-20.09.47:102][665]LogWindows: Error: [Callstack] 0x00007ff779058f9a UnrealEditor.exe!__scrt_common_main_seh() [D:\a\_work\1\s\src\vctools\crt\vcstartup\src\startup\exe_common.inl:288]

[2026.06.08-20.09.47:102][665]LogWindows: Error: [Callstack] 0x00007ff85b14259d KERNEL32.DLL!UnknownFunction []

========= Cooking Call Stack ==========

[2026.06.08-19.50.24:766][918]UATHelper: Error: Packaging (Windows): LogWindows: Error: [Callstack] 0x00007ffeebec230e UnrealEditor-Engine.dll!UStaticMesh::ClearAllCachedCookedPlatformData() [P:\dev\UnrealEngine\Engine\Source\Runtime\Engine\Private\StaticMesh.cpp:6567]

[2026.06.08-19.50.24:766][918]UATHelper: Error: Packaging (Windows): LogWindows: Error: [Callstack] 0x00007ffee8142623 UnrealEditor-UnrealEd.dll!UE::Cook::FPendingCookedPlatformData::ClearCachedCookedPlatformData() [P:\dev\UnrealEngine\Engine\Source\Editor\UnrealEd\Private\Cooker\CookPackageData.cpp:2059]

[2026.06.08-19.50.24:766][918]UATHelper: Error: Packaging (Windows): LogWindows: Error: [Callstack] 0x00007ffee90ecc57 UnrealEditor-UnrealEd.dll!UCookOnTheFlyServer::ReleaseCookedPlatformData() [P:\dev\UnrealEngine\Engine\Source\Editor\UnrealEd\Private\CookOnTheFlyServer.cpp:4497]

[2026.06.08-19.50.24:766][918]UATHelper: Error: Packaging (Windows): LogWindows: Error: [Callstack] 0x00007ffee90e8bd3 UnrealEditor-UnrealEd.dll!UCookOnTheFlyServer::PumpRuntimeSaves() [P:\dev\UnrealEngine\Engine\Source\Editor\UnrealEd\Private\CookOnTheFlyServer.cpp:5165]

[2026.06.08-19.50.24:766][918]UATHelper: Error: Packaging (Windows): LogWindows: Error: [Callstack] 0x00007ffee90f6cea UnrealEditor-UnrealEd.dll!UCookOnTheFlyServer::TickMainCookLoop() [P:\dev\UnrealEngine\Engine\Source\Editor\UnrealEd\Private\CookOnTheFlyServer.cpp:1575]

[2026.06.08-19.50.24:766][918]UATHelper: Error: Packaging (Windows): LogWindows: Error: [Callstack] 0x00007ffee90f62e4 UnrealEditor-UnrealEd.dll!UCookOnTheFlyServer::TickCookByTheBook() [P:\dev\UnrealEngine\Engine\Source\Editor\UnrealEd\Private\CookOnTheFlyServer.cpp:1422]

[2026.06.08-19.50.24:766][918]UATHelper: Error: Packaging (Windows): LogWindows: Error: [Callstack] 0x00007ffee7f05dbd UnrealEditor-UnrealEd.dll!UCookCommandlet::RunCookByTheBookCook() [P:\dev\UnrealEngine\Engine\Source\Editor\UnrealEd\Private\Commandlets\CookCommandlet.cpp:607]

[2026.06.08-19.50.24:766][918]UATHelper: Error: Packaging (Windows): LogWindows: Error: [Callstack] 0x00007ffee7ecb26a UnrealEditor-UnrealEd.dll!UCookCommandlet::CookByTheBook() [P:\dev\UnrealEngine\Engine\Source\Editor\UnrealEd\Private\Commandlets\CookCommandlet.cpp:559]

[2026.06.08-19.50.24:766][918]UATHelper: Error: Packaging (Windows): LogWindows: Error: [Callstack] 0x00007ffee7ee9513 UnrealEditor-UnrealEd.dll!UCookCommandlet::Main() [P:\dev\UnrealEngine\Engine\Source\Editor\UnrealEd\Private\Commandlets\CookCommandlet.cpp:278]

[2026.06.08-19.50.24:766][918]UATHelper: Error: Packaging (Windows): LogWindows: Error: [Callstack] 0x00007ff7bcf9a5d1 UnrealEditor-Cmd.exe!FEngineLoop::PreInitPostStartupScreen() [P:\dev\UnrealEngine\Engine\Source\Runtime\Launch\Private\LaunchEngineLoop.cpp:4053]

[2026.06.08-19.50.24:777][918]UATHelper: Error: Packaging (Windows): LogWindows: Error: [Callstack] 0x00007ff7bcf90a1b UnrealEditor-Cmd.exe!GuardedMain() [P:\dev\UnrealEngine\Engine\Source\Runtime\Launch\Private\Launch.cpp:146]

[2026.06.08-19.50.24:777][918]UATHelper: Error: Packaging (Windows): LogWindows: Error: [Callstack] 0x00007ff7bcf90d0a UnrealEditor-Cmd.exe!GuardedMainWrapper() [P:\dev\UnrealEngine\Engine\Source\Runtime\Launch\Private\Windows\LaunchWindows.cpp:123]

[2026.06.08-19.50.24:777][918]UATHelper: Error: Packaging (Windows): LogWindows: Error: [Callstack] 0x00007ff7bcf94590 UnrealEditor-Cmd.exe!LaunchWindowsStartup() [P:\dev\UnrealEngine\Engine\Source\Runtime\Launch\Private\Windows\LaunchWindows.cpp:277]

[2026.06.08-19.50.24:777][918]UATHelper: Error: Packaging (Windows): LogWindows: Error: [Callstack] 0x00007ff7bcfa5be4 UnrealEditor-Cmd.exe!WinMain() [P:\dev\UnrealEngine\Engine\Source\Runtime\Launch\Private\Windows\LaunchWindows.cpp:334]

[2026.06.08-19.50.24:777][918]UATHelper: Error: Packaging (Windows): LogWindows: Error: [Callstack] 0x00007ff7bcfa82f6 UnrealEditor-Cmd.exe!__scrt_common_main_seh() [D:\a\_work\1\s\src\vctools\crt\vcstartup\src\startup\exe_common.inl:288]

[2026.06.08-19.50.24:777][918]UATHelper: Error: Packaging (Windows): LogWindows: Error: [Callstack] 0x00007ff85b14259d KERNEL32.DLL!UnknownFunction []