WMR: Crash in VR Edit Mode

UE4Editor_Engine!UGameViewportClient::GetWindow() [d:\build\++ue4\sync\engine\source\runtime\engine\classes\engine\gameviewportclient.h:312]
UE4Editor_WindowsMixedRealityHMD!WindowsMixedReality::FWindowsMixedRealityHMD::OnStartGameFrame() [d:\build\++ue4\sync\engine\plugins\runtime\windowsmixedreality\source\windowsmixedrealityhmd\private\windowsmixedrealityhmd.cpp:296]
UE4Editor_Engine!UWorld::Tick() [d:\build\++ue4\sync\engine\source\runtime\engine\private\leveltick.cpp:1322]
UE4Editor_UnrealEd!UEditorEngine::Tick() [d:\build\++ue4\sync\engine\source\editor\unrealed\private\editorengine.cpp:1543]
UE4Editor_UnrealEd!UUnrealEdEngine::Tick() [d:\build\++ue4\sync\engine\source\editor\unrealed\private\unrealedengine.cpp:403]
UE4Editor!FEngineLoop::Tick() [d:\build\++ue4\sync\engine\source\runtime\launch\private\launchengineloop.cpp:3699]
UE4Editor!GuardedMain() [d:\build\++ue4\sync\engine\source\runtime\launch\private\launch.cpp:174]
UE4Editor!GuardedMainWrapper() [d:\build\++ue4\sync\engine\source\runtime\launch\private\windows\launchwindows.cpp:145]
UE4Editor!WinMain() [d:\build\++ue4\sync\engine\source\runtime\launch\private\windows\launchwindows.cpp:276]
UE4Editor!__scrt_common_main_seh() [f:\dd\vctools\crt\vcstartup\src\startup\exe_common.inl:283]
kernel32
ntdll