Crash occurs when right-clicking in graph of a blueprint with a null parent class

UE4Editor_BlueprintGraph!UBlueprintVariableNodeSpawner::GetUiSpec() blueprintvariablenodespawner.cpp:182 
UE4Editor_Kismet!FBlueprintActionMenuItemFactory::GetActionUiSignature() blueprintactionmenubuilder.cpp:240 
UE4Editor_Kismet!FBlueprintActionMenuItemFactory::MakeActionMenuItem() blueprintactionmenubuilder.cpp:109 
UE4Editor_Kismet!FBlueprintActionMenuBuilderImpl::FMenuSectionDefinition::MakeMenuItems() blueprintactionmenubuilder.cpp:450 
UE4Editor_Kismet!FBlueprintActionMenuBuilder::RebuildActionList() blueprintactionmenubuilder.cpp:532 
UE4Editor_Kismet!FBlueprintActionMenuUtils::MakeContextMenu() blueprintactionmenuutils.cpp:686 
UE4Editor_Kismet!SBlueprintActionMenu::CollectAllActions() sblueprintactionmenu.cpp:455 
UE4Editor_Kismet!TBaseSPMethodDelegateInstance<0,SBlueprintActionMenu,0,TTypeWrapper<void> __cdecl() delegateinstancesimpl.h:327 
UE4Editor_Kismet!TBaseSPMethodDelegateInstance<0,SBlueprintActionMenu,0,void __cdecl() delegateinstancesimpl.h:434 
UE4Editor_GraphEditor!SGraphActionMenu::RefreshAllActions() sgraphactionmenu.cpp:351 
UE4Editor_GraphEditor!SGraphActionMenu::Construct() sgraphactionmenu.cpp:341 
UE4Editor_Kismet!TDecl<SGraphActionMenu,RequiredArgs::T0RequiredArgs>::operator<<=() declarativesyntaxsupport.h:1087 
UE4Editor_Kismet!SBlueprintActionMenu::Construct() sblueprintactionmenu.cpp:264 
UE4Editor_Kismet!TDecl<SBlueprintActionMenu,RequiredArgs::T1RequiredArgs<TSharedRef<FBlueprintEditor,0> && __ptr64> >::operator<<=() declarativesyntaxsupport.h:1087
UE4Editor_Kismet!FBlueprintEditor::OnCreateGraphActionMenu() blueprinteditor.cpp:3135 
UE4Editor_Kismet!TMemberFunctionCaller<FBlueprintEditor,FActionMenuContent() delegateinstanceinterface.h:165 
UE4Editor_Kismet!UE4Tuple_Private::TTupleImpl<TIntegerSequence<unsigned int> >::ApplyAfter<TMemberFunctionCaller<FBlueprintEditor,FActionMenuCont tuple.h:504
UE4Editor_Kismet!TBaseSPMethodDelegateInstance<0,FBlueprintEditor,0,FActionMenuContent __cdecl() delegateinstancesimpl.h:327 
UE4Editor_GraphEditor!TBaseDelegate<FActionMenuContent,UEdGraph * __ptr64,FVector2D const & __ptr64,TArray<UEdGraphPin * __ptr64,FDefaultAllocator> co delegatesignatureimpl.inl:537
UE4Editor_GraphEditor!SGraphEditorImpl::GraphEd_OnGetContextMenuFor() sgrapheditorimpl.cpp:509 
UE4Editor_GraphEditor!TMemberFunctionCaller<SGraphEditorImpl,FActionMenuContent() delegateinstanceinterface.h:165 
UE4Editor_GraphEditor!UE4Tuple_Private::TTupleImpl<TIntegerSequence<unsigned int> >::ApplyAfter<TMemberFunctionCaller<SGraphEditorImpl,FActionMenuCont tuple.h:504
UE4Editor_GraphEditor!TBaseSPMethodDelegateInstance<0,SGraphEditorImpl,0,FActionMenuContent __cdecl() delegateinstancesimpl.h:327 
UE4Editor_GraphEditor!TBaseDelegate<FActionMenuContent,FGraphContextMenuArguments const & __ptr64>::Execute() delegatesignatureimpl.inl:537 
UE4Editor_GraphEditor!SGraphPanel::SummonContextMenu() sgraphpanel.cpp:1035 
UE4Editor_GraphEditor!SGraphPanel::OnSummonContextMenu() sgraphpanel.cpp:761 
UE4Editor_GraphEditor!SNodePanel::OnMouseButtonUp() snodepanel.cpp:831 
UE4Editor_GraphEditor!SGraphPanel::OnMouseButtonUp() sgraphpanel.cpp:643 
UE4Editor_Slate!<lambda_8d0e9a1da76abd0a756a3a9d775f5ed1>::operator() slateapplication.cpp:5016 
UE4Editor_Slate!FEventRouter::Route<FReply,FEventRouter::FToLeafmostPolicy,FPointerEvent,<lambda_8d0e9a1da76abd0a756a3a9d775f5ed1> >() slateapplication.cpp:239
UE4Editor_Slate!FSlateApplication::RoutePointerUpEvent() slateapplication.cpp:5005 
UE4Editor_Slate!FSlateApplication::ProcessMouseButtonUpEvent() slateapplication.cpp:5472 
UE4Editor_Slate!FSlateApplication::OnMouseUp() slateapplication.cpp:5449 
UE4Editor_Core!FWindowsApplication::ProcessDeferredMessage() windowsapplication.cpp:1698 
UE4Editor_Core!FWindowsApplication::DeferMessage() windowsapplication.cpp:2120 
UE4Editor_Core!FWindowsApplication::ProcessMessage() windowsapplication.cpp:867 
UE4Editor_Core!FWindowsApplication::AppWndProc() windowsapplication.cpp:714 
user32!<Unknown> 
user32!<Unknown> 
UE4Editor_Core!FWindowsPlatformMisc::PumpMessages() windowsplatformmisc.cpp:980 
UE4Editor!FEngineLoop::Tick() launchengineloop.cpp:3019 
UE4Editor!GuardedMain() launch.cpp:166 
UE4Editor!GuardedMainWrapper() launchwindows.cpp:134 
UE4Editor!WinMain() launchwindows.cpp:210 
UE4Editor!__scrt_common_main_seh() exe_common.inl:264 
kernel32!<Unknown> 
ntdll!<Unknown>