Pressing "+" element in landscape grass type asset crashes editor

Creating a landscape grass type and then pressing the + to add an element crashes the editor.

Frequency: 2/2

Crashreporter: not currently available

1. Open Editor (any project)
2. In content browser, RMB>Miscellaneous>Landscape Grass Type
3. Open Landscape Grass Type
4. Press the + sign to add an element

Result:

Editor crashes.

Expected:

An element is added to the landscape grass type asset that can be edited.

MachineId:4E82586D46B558EA69EF0EAA821297B1
EpicAccountId:1558531203f84e81b70959b8a59badef

Unknown exception - code 00000001 (first/second chance not available)

"Assertion failed: CurrentWorld [Link Removed] [Line: 180]
"

UE4Editor_Core!FDebug::AssertFailed() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\core\private\misc\outputdevice.cpp:354]
UE4Editor_Landscape!FActorIteratorState::FActorIteratorState() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\engine\public\engineutils.h:182]
UE4Editor_Landscape!ULandscapeGrassType::PostEditChangeProperty() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\landscape\private\landscapegrass.cpp:781]
UE4Editor_CoreUObject!UObject::PostEditChangeChainProperty() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\coreuobject\private\uobject\obj.cpp:374]
UE4Editor_PropertyEditor!FPropertyNode::NotifyPostChange() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\editor\propertyeditor\private\propertynode.cpp:1979]
UE4Editor_PropertyEditor!FPropertyValueImpl::AddChild() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\editor\propertyeditor\private\propertyhandleimpl.cpp:1111]
UE4Editor_PropertyEditor!FPropertyHandleArray::AddItem() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\editor\propertyeditor\private\propertyhandleimpl.cpp:2885]
UE4Editor_PropertyEditor!FPropertyEditor::OnAddItem() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\editor\propertyeditor\private\presentation\propertyeditor\propertyeditor.cpp:204]
UE4Editor_PropertyEditor!TBaseSPMethodDelegateInstance<0,FPropertyEditor,0,TTypeWrapper<void> __cdecl(void)>::Execute() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\core\public\delegates\delegateinstancesimpl_variadics.inl:282]
UE4Editor_PropertyEditor!TBaseSPMethodDelegateInstance<0,FPropertyEditor,0,void __cdecl(void)>::ExecuteIfSafe() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\core\public\delegates\delegateinstancesimpl_variadics.inl:388]
UE4Editor_PropertyEditor!SDetailsViewBase::Tick() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\editor\propertyeditor\private\sdetailsviewbase.cpp:702]
UE4Editor_SlateCore!SWidget::Paint() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\slatecore\private\widgets\swidget.cpp:700]
UE4Editor_SlateCore!SCompoundWidget::OnPaint() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\slatecore\private\widgets\scompoundwidget.cpp:25]
UE4Editor_Slate!SBorder::OnPaint() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\slate\private\widgets\layout\sborder.cpp:94]
UE4Editor_SlateCore!SWidget::Paint() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\slatecore\private\widgets\swidget.cpp:703]
UE4Editor_SlateCore!SOverlay::OnPaint() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\slatecore\private\widgets\soverlay.cpp:95]
UE4Editor_SlateCore!SWidget::Paint() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\slatecore\private\widgets\swidget.cpp:703]
UE4Editor_SlateCore!SPanel::PaintArrangedChildren() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\slatecore\private\widgets\spanel.cpp:39]
UE4Editor_SlateCore!SPanel::OnPaint() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\slatecore\private\widgets\spanel.cpp:19]
UE4Editor_SlateCore!SWidget::Paint() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\slatecore\private\widgets\swidget.cpp:703]
UE4Editor_SlateCore!SCompoundWidget::OnPaint() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\slatecore\private\widgets\scompoundwidget.cpp:25]
UE4Editor_SlateCore!SWidget::Paint() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\slatecore\private\widgets\swidget.cpp:703]
UE4Editor_SlateCore!SPanel::PaintArrangedChildren() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\slatecore\private\widgets\spanel.cpp:39]
UE4Editor_Slate!SSplitter::OnPaint() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\slate\private\widgets\layout\ssplitter.cpp:166]
UE4Editor_SlateCore!SWidget::Paint() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\slatecore\private\widgets\swidget.cpp:703]
UE4Editor_SlateCore!SOverlay::OnPaint() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\slatecore\private\widgets\soverlay.cpp:95]
UE4Editor_SlateCore!SWidget::Paint() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\slatecore\private\widgets\swidget.cpp:703]
UE4Editor_SlateCore!SCompoundWidget::OnPaint() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\slatecore\private\widgets\scompoundwidget.cpp:25]
UE4Editor_SlateCore!SWidget::Paint() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\slatecore\private\widgets\swidget.cpp:703]
UE4Editor_SlateCore!SPanel::PaintArrangedChildren() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\slatecore\private\widgets\spanel.cpp:39]
UE4Editor_SlateCore!SPanel::OnPaint() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\slatecore\private\widgets\spanel.cpp:19]
UE4Editor_SlateCore!SWidget::Paint() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\slatecore\private\widgets\swidget.cpp:703]
UE4Editor_SlateCore!SCompoundWidget::OnPaint() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\slatecore\private\widgets\scompoundwidget.cpp:25]
UE4Editor_SlateCore!SWidget::Paint() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\slatecore\private\widgets\swidget.cpp:703]
UE4Editor_SlateCore!SCompoundWidget::OnPaint() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\slatecore\private\widgets\scompoundwidget.cpp:25]
UE4Editor_Slate!SBorder::OnPaint() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\slate\private\widgets\layout\sborder.cpp:94]
UE4Editor_SlateCore!SWidget::Paint() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\slatecore\private\widgets\swidget.cpp:703]
UE4Editor_SlateCore!SOverlay::OnPaint() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\slatecore\private\widgets\soverlay.cpp:95]
UE4Editor_SlateCore!SWidget::Paint() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\slatecore\private\widgets\swidget.cpp:703]
UE4Editor_SlateCore!SPanel::PaintArrangedChildren() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\slatecore\private\widgets\spanel.cpp:39]
UE4Editor_SlateCore!SPanel::OnPaint() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\slatecore\private\widgets\spanel.cpp:19]
UE4Editor_SlateCore!SWidget::Paint() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\slatecore\private\widgets\swidget.cpp:703]
UE4Editor_SlateCore!SCompoundWidget::OnPaint() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\slatecore\private\widgets\scompoundwidget.cpp:25]
UE4Editor_SlateCore!SWidget::Paint() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\slatecore\private\widgets\swidget.cpp:703]
UE4Editor_SlateCore!SPanel::PaintArrangedChildren() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\slatecore\private\widgets\spanel.cpp:39]
UE4Editor_Slate!SSplitter::OnPaint() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\slate\private\widgets\layout\ssplitter.cpp:166]
UE4Editor_SlateCore!SWidget::Paint() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\slatecore\private\widgets\swidget.cpp:703]
UE4Editor_SlateCore!SOverlay::OnPaint() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\slatecore\private\widgets\soverlay.cpp:95]
UE4Editor_SlateCore!SWidget::Paint() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\slatecore\private\widgets\swidget.cpp:703]
UE4Editor_SlateCore!SCompoundWidget::OnPaint() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\slatecore\private\widgets\scompoundwidget.cpp:25]
UE4Editor_SlateCore!SWidget::Paint() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\slatecore\private\widgets\swidget.cpp:703]
UE4Editor_SlateCore!SPanel::PaintArrangedChildren() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\slatecore\private\widgets\spanel.cpp:39]
UE4Editor_SlateCore!SPanel::OnPaint() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\slatecore\private\widgets\spanel.cpp:19]
UE4Editor_SlateCore!SWidget::Paint() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\slatecore\private\widgets\swidget.cpp:703]
UE4Editor_SlateCore!SPanel::PaintArrangedChildren() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\slatecore\private\widgets\spanel.cpp:39]
UE4Editor_SlateCore!SPanel::OnPaint() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\slatecore\private\widgets\spanel.cpp:19]
UE4Editor_SlateCore!SWidget::Paint() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\slatecore\private\widgets\swidget.cpp:703]
UE4Editor_SlateCore!SOverlay::OnPaint() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\slatecore\private\widgets\soverlay.cpp:95]
UE4Editor_SlateCore!SWidget::Paint() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\slatecore\private\widgets\swidget.cpp:703]
UE4Editor_SlateCore!SCompoundWidget::OnPaint() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\slatecore\private\widgets\scompoundwidget.cpp:25]
UE4Editor_SlateCore!SWidget::Paint() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\slatecore\private\widgets\swidget.cpp:703]
UE4Editor_SlateCore!SWindow::PaintWindow() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\slatecore\private\widgets\swindow.cpp:1663]
UE4Editor_Slate!FSlateApplication::DrawWindowAndChildren() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:964]
UE4Editor_Slate!FSlateApplication::DrawWindowAndChildren() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:1040]
UE4Editor_Slate!FSlateApplication::PrivateDrawWindows() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:1182]
UE4Editor_Slate!FSlateApplication::DrawWindows() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:927]
UE4Editor_Slate!FSlateApplication::Tick() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:1441]
UE4Editor!FEngineLoop::Tick() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\launch\private\launchengineloop.cpp:2443]
UE4Editor!GuardedMain() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\launch\private\launch.cpp:142]
UE4Editor!GuardedMainWrapper() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\launch\private\windows\launchwindows.cpp:126]
UE4Editor!WinMain() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\launch\private\windows\launchwindows.cpp:200]