[CrashReport] Fatal error: Cast of nullptr to Actor failed - UE4Editor_CoreUObject!CastLogError()

Fatal error: [File:D:\Build\++UE4+Release-4.16+Compile\Sync\Engine\Source\Runtime\CoreUObject\Private\Templates\Casts.cpp] [Line: 10] Cast of nullptr to Actor failed

UE4Editor_CoreUObject!CastLogError() [casts.cpp:11]
UE4Editor_UnrealEd!CastChecked<AActor,UObject>() [casts.h:211]
UE4Editor_UnrealEd!UEditorEngine::DoConvertActors() [editorengine.cpp:5665]
UE4Editor_UnrealEd!UEditorEngine::ConvertActors() [editorengine.cpp:5550]
UE4Editor_DetailCustomizations!FActorDetails::OnConvertActor() [actordetails.cpp:177]
UE4Editor_DetailCustomizations!TBaseSPMethodDelegateInstance<0,FActorDetails,0,TTypeWrapper<void> __cdecl() [delegateinstancesimpl.h:327]
UE4Editor_DetailCustomizations!TBaseSPMethodDelegateInstance<0,FActorDetails,0,void __cdecl() [delegateinstancesimpl.h:434]
UE4Editor_ClassViewer!SClassViewer::OnClassViewerSelectionChanged() [sclassviewer.cpp:2428]
UE4Editor_ClassViewer!TBaseSPMethodDelegateInstance<0,SClassViewer,0,TTypeWrapper<void> __cdecl() [delegateinstancesimpl.h:327]
UE4Editor_ClassViewer!TBaseSPMethodDelegateInstance<0,SClassViewer,0,void __cdecl() [delegateinstancesimpl.h:434]
UE4Editor_ClassViewer!TBaseDelegate<void,TSharedPtr<FClassViewerNode,0>,enum ESelectInfo::Type>::ExecuteIfBound() [delegatesignatureimpl.inl:624]
UE4Editor_ClassViewer!SListView<TSharedPtr<FClassViewerNode,0> >::Private_SignalSelectionChanged() [slistview.h:735]
UE4Editor_ClassViewer!STableRow<TSharedPtr<FString,0> >::OnMouseButtonUp() [stablerow.h:476]
UE4Editor_Slate!<lambda_8d0e9a1da76abd0a756a3a9d775f5ed1>::operator() [slateapplication.cpp:5049]
UE4Editor_Slate!FEventRouter::Route<FReply,FEventRouter::FToLeafmostPolicy,FPointerEvent,<lambda_8d0e9a1da76abd0a756a3a9d775f5ed1> >() [slateapplication.cpp:239]
UE4Editor_Slate!FSlateApplication::RoutePointerUpEvent() [slateapplication.cpp:5038]
UE4Editor_Slate!FSlateApplication::ProcessMouseButtonUpEvent() [slateapplication.cpp:5515]
UE4Editor_Slate!FSlateApplication::OnMouseUp() [slateapplication.cpp:5495]
UE4Editor_Core!FWindowsApplication::ProcessDeferredMessage() [windowsapplication.cpp:1704]
UE4Editor_Core!FWindowsApplication::DeferMessage() [windowsapplication.cpp:2127]
UE4Editor_Core!FWindowsApplication::ProcessMessage() [windowsapplication.cpp:867]
UE4Editor_Core!FWindowsApplication::AppWndProc() [windowsapplication.cpp:714]
user32!UserCallWinProcCheckWow()
user32!DispatchMessageWorker()
UE4Editor_Core!FWindowsPlatformMisc::PumpMessages() [windowsplatformmisc.cpp:1009]
UE4Editor!FEngineLoop::Tick() [launchengineloop.cpp:3058]
UE4Editor!GuardedMain() [launch.cpp:166]
UE4Editor!GuardedMainWrapper() [launchwindows.cpp:134]
UE4Editor!WinMain() [launchwindows.cpp:210]
UE4Editor!__scrt_common_main_seh() [exe_common.inl:253]
kernel32!BaseThreadInitThunk()
ntdll!RtlUserThreadStart()