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

Fix UE-51650

i have this problem UE4CC-Windows-58DC12AF4B97F057BD108FBFF569B2E9_0000

I am not able to find world outliner how to enable it?

Undefined sysmbol: typeinfo for AActor when cross-compile linux dedicated server on windows

Delay nodes occasionally don't fire the "Completed" output in a nativized build

An error occurred while trying to generate project files !?

I've been trying to follow the demo for Unreal 4 where you create the office but my unreal blanks out and crashes every time I try after I'm a few videos in everytime. It gives me a large error list everytime

I've been trying to follow demo for Unreal 4 where you create office but my unreal blanks out and crashes every time I try after I'm a few videos in everytime. It gives me a large error list everytime

After I install the program,I open it,but it crashes.And sometimes it turns to the missing of the globalshader...SM4.bin

My map looks so rigged because part of the skybox is missing it says "Your scene contains a skydome mesh with a sky material but it does not cover that part of the screen