Editor crashes when building a level containing landscape if Preview Rendering settings are set to Default High End Mobile.

Editor crashes when building a level containing landscape if Preview Rendering settings are set to Default High End Mobile.

This is a regression.
This is working on 4.16 3-3561208
This is not working in 4.17.1-3586342 and Main.

1. Open new project (Blank) without starter content
2. Select Landscape Mode> Create
3. Using Sculpt tool, click on landscape to raise height
4. Select Settings > Preview Rendering Level > High-End Mobile / Metal > Default High-End Mobile
5. Click Build (all levels)

Result: Engine crash

Assertion failed: !IsInRenderingThread() [Link Removed] [Line: 313]

KERNELBASE.dll!0x0000000009513C58
UE4Editor-Core.dll!FOutputDeviceWindowsError::Serialize() [d:\build\++ue4+release-4.17+compile\sync\engine\source\runtime\core\private\windows\windowsplatformoutputdevices.cpp:120]
UE4Editor-Core.dll!FOutputDevice::Logf__VA() [d:\build\++ue4+release-4.17+compile\sync\engine\source\runtime\core\private\misc\outputdevice.cpp:70]
UE4Editor-Core.dll!FDebug::AssertFailed() [d:\build\++ue4+release-4.17+compile\sync\engine\source\runtime\core\private\misc\assertionmacros.cpp:349]
UE4Editor-Landscape.dll!FLandscapeComponentDerivedData::GetRenderData() [d:\build\++ue4+release-4.17+compile\sync\engine\source\runtime\landscape\private\landscaperendermobile.cpp:322]
UE4Editor-Landscape.dll!FLandscapeComponentSceneProxyMobile::FLandscapeComponentSceneProxyMobile() [d:\build\++ue4+release-4.17+compile\sync\engine\source\runtime\landscape\private\landscaperendermobile.cpp:254]
UE4Editor-Landscape.dll!ULandscapeComponent::CreateSceneProxy() [d:\build\++ue4+release-4.17+compile\sync\engine\source\runtime\landscape\private\landscape.cpp:971]
UE4Editor-Renderer.dll!FScene::AddPrimitive() [d:\build\++ue4+release-4.17+compile\sync\engine\source\runtime\renderer\private\rendererscene.cpp:718]
UE4Editor-Engine.dll!UPrimitiveComponent::CreateRenderState_Concurrent() [d:\build\++ue4+release-4.17+compile\sync\engine\source\runtime\engine\private\components\primitivecomponent.cpp:436]
UE4Editor-Engine.dll!UActorComponent::ExecuteRegisterEvents() [d:\build\++ue4+release-4.17+compile\sync\engine\source\runtime\engine\private\components\actorcomponent.cpp:1243]
UE4Editor-Engine.dll!UActorComponent::RegisterComponentWithWorld() [d:\build\++ue4+release-4.17+compile\sync\engine\source\runtime\engine\private\components\actorcomponent.cpp:974]
UE4Editor-Engine.dll!AActor::IncrementalRegisterComponents() [d:\build\++ue4+release-4.17+compile\sync\engine\source\runtime\engine\private\actor.cpp:4123]
UE4Editor-Engine.dll!ULevel::IncrementalUpdateComponents() [d:\build\++ue4+release-4.17+compile\sync\engine\source\runtime\engine\private\level.cpp:911]
UE4Editor-Engine.dll!UWorld::UpdateWorldComponents() [d:\build\++ue4+release-4.17+compile\sync\engine\source\runtime\engine\private\world.cpp:1586]
UE4Editor-UnrealEd.dll!FUnrealEdMisc::CB_MapChange() [d:\build\++ue4+release-4.17+compile\sync\engine\source\editor\unrealed\private\unrealedmisc.cpp:1028]
UE4Editor-UnrealEd.dll!TBaseRawMethodDelegateInstance<0,FUnrealEdMisc,void __cdecl(unsigned int)>::ExecuteIfSafe() [d:\build\++ue4+release-4.17+compile\sync\engine\source\runtime\core\public\delegates\delegateinstancesimpl.h:648]
UE4Editor-UnrealEd.dll!TBaseMulticastDelegate<void,unsigned int>::Broadcast() [d:\build\++ue4+release-4.17+compile\sync\engine\source\runtime\core\public\delegates\delegatesignatureimpl.inl:937]
UE4Editor-UnrealEd.dll!UEditorEngine::RebuildMap() [d:\build\++ue4+release-4.17+compile\sync\engine\source\editor\unrealed\private\editorserver.cpp:1650]
UE4Editor-UnrealEd.dll!UEditorEngine::Map_Rebuild() [d:\build\++ue4+release-4.17+compile\sync\engine\source\editor\unrealed\private\editorserver.cpp:1514]
UE4Editor-UnrealEd.dll!UEditorEngine::HandleMapCommand() [d:\build\++ue4+release-4.17+compile\sync\engine\source\editor\unrealed\private\editorserver.cpp:5991]
UE4Editor-UnrealEd.dll!UEditorEngine::Exec() [d:\build\++ue4+release-4.17+compile\sync\engine\source\editor\unrealed\private\editorserver.cpp:5468]
UE4Editor-UnrealEd.dll!UUnrealEdEngine::Exec() [d:\build\++ue4+release-4.17+compile\sync\engine\source\editor\unrealed\private\unrealedsrv.cpp:672]
UE4Editor-UnrealEd.dll!FBuildAllHandler::ProcessBuild() [d:\build\++ue4+release-4.17+compile\sync\engine\source\editor\unrealed\private\editorbuildutils.cpp:984]
UE4Editor-UnrealEd.dll!FEditorBuildUtils::EditorBuild() [d:\build\++ue4+release-4.17+compile\sync\engine\source\editor\unrealed\private\editorbuildutils.cpp:427]
UE4Editor-LevelEditor.dll!FLevelEditorActionCallbacks::Build_Execute() [d:\build\++ue4+release-4.17+compile\sync\engine\source\editor\leveleditor\private\leveleditoractions.cpp:633]
UE4Editor-LevelEditor.dll!TBaseStaticDelegateInstance<void __cdecl(void)>::ExecuteIfSafe() [d:\build\++ue4+release-4.17+compile\sync\engine\source\runtime\core\public\delegates\delegateinstancesimpl.h:1027]
UE4Editor-Slate.dll!FUICommandList::ExecuteAction() [d:\build\++ue4+release-4.17+compile\sync\engine\source\runtime\slate\private\framework\commands\uicommandlist.cpp:97]
UE4Editor-Slate.dll!SToolBarButtonBlock::OnClicked() [d:\build\++ue4+release-4.17+compile\sync\engine\source\runtime\slate\private\framework\multibox\stoolbarbuttonblock.cpp:305]
UE4Editor-Slate.dll!TMemberFunctionCaller<SToolBarButtonBlock,FReply (__cdecl SToolBarButtonBlock::*)(void) __ptr64>::operator()<>() [d:\build\++ue4+release-4.17+compile\sync\engine\source\runtime\core\public\delegates\delegateinstanceinterface.h:165]
UE4Editor-Slate.dll!UE4Tuple_Private::TTupleImpl<TIntegerSequence<unsigned int> >::ApplyAfter<TMemberFunctionCaller<SToolBarButtonBlock,FReply (__cdecl SToolBarButtonBlock::*)(void) __ptr64> >() [d:\build\++ue4+release-4.17+compile\sync\engine\source\runtime\core\public\templates\tuple.h:497]
UE4Editor-Slate.dll!TBaseSPMethodDelegateInstance<0,SToolBarButtonBlock,0,FReply __cdecl(void)>::Execute() [d:\build\++ue4+release-4.17+compile\sync\engine\source\runtime\core\public\delegates\delegateinstancesimpl.h:327]
UE4Editor-Slate.dll!TBaseDelegate<FReply>::Execute() [d:\build\++ue4+release-4.17+compile\sync\engine\source\runtime\core\public\delegates\delegatesignatureimpl.inl:537]
UE4Editor-Slate.dll!SButton::OnMouseButtonUp() [d:\build\++ue4+release-4.17+compile\sync\engine\source\runtime\slate\private\widgets\input\sbutton.cpp:282]
UE4Editor-Slate.dll!<lambda_1002768c627006711ef2f351a87ec0e7>::operator()() [d:\build\++ue4+release-4.17+compile\sync\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:5199]
UE4Editor-Slate.dll!FEventRouter::Route<FReply,FEventRouter::FToLeafmostPolicy,FPointerEvent,<lambda_1002768c627006711ef2f351a87ec0e7> >() [d:\build\++ue4+release-4.17+compile\sync\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:232]
UE4Editor-Slate.dll!FSlateApplication::RoutePointerUpEvent() [d:\build\++ue4+release-4.17+compile\sync\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:5188]
UE4Editor-Slate.dll!FSlateApplication::ProcessMouseButtonUpEvent() [d:\build\++ue4+release-4.17+compile\sync\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:5690]
UE4Editor-Slate.dll!FSlateApplication::OnMouseUp() [d:\build\++ue4+release-4.17+compile\sync\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:5670]
UE4Editor-Core.dll!FWindowsApplication::ProcessDeferredMessage() [d:\build\++ue4+release-4.17+compile\sync\engine\source\runtime\core\private\windows\windowsapplication.cpp:1718]
UE4Editor-Core.dll!FWindowsApplication::DeferMessage() [d:\build\++ue4+release-4.17+compile\sync\engine\source\runtime\core\private\windows\windowsapplication.cpp:2161]
UE4Editor-Core.dll!FWindowsApplication::ProcessMessage() [d:\build\++ue4+release-4.17+compile\sync\engine\source\runtime\core\private\windows\windowsapplication.cpp:881]
UE4Editor-Core.dll!FWindowsApplication::AppWndProc() [d:\build\++ue4+release-4.17+compile\sync\engine\source\runtime\core\private\windows\windowsapplication.cpp:721]
USER32.dll!0x000000000C961C24
USER32.dll!0x000000000C96156C
UE4Editor-Core.dll!FWindowsPlatformMisc::PumpMessages() [d:\build\++ue4+release-4.17+compile\sync\engine\source\runtime\core\private\windows\windowsplatformmisc.cpp:1009]
UE4Editor.exe!FEngineLoop::Tick() [d:\build\++ue4+release-4.17+compile\sync\engine\source\runtime\launch\private\launchengineloop.cpp:3151]
UE4Editor.exe!GuardedMain() [d:\build\++ue4+release-4.17+compile\sync\engine\source\runtime\launch\private\launch.cpp:166]
UE4Editor.exe!GuardedMainWrapper() [d:\build\++ue4+release-4.17+compile\sync\engine\source\runtime\launch\private\windows\launchwindows.cpp:134]
UE4Editor.exe!WinMain() [d:\build\++ue4+release-4.17+compile\sync\engine\source\runtime\launch\private\windows\launchwindows.cpp:210]
UE4Editor.exe!__scrt_common_main_seh() [f:\dd\vctools\crt\vcstartup\src\startup\exe_common.inl:253]
KERNEL32.DLL!0x000000000A5A8364
ntdll.dll!0x000000000CBE7091
ntdll.dll!0x000000000CBE7091