This issue has been closed as 'Won't Fix' due to an extended period of time without updates. If this issue is important to you please let us know by posting on the AnswerHub or UDN, and Epic will re-open the ticket for further review.
Setting the brush shape of the root component for a custom volume BP causes the editor to immediately crash.
1. Launch UE4 Editor (any project)
2. File -> Add code to project
3. Add new class with Volume set as parent
4. In the header file in Visual Studios, change UClass() to UClass(Blueprintable)
5. Build the project and relaunch
6. Create blueprint based on new class
7. In component tab, select the Root Component
8. Set the brush shape under Brush Settings to anything in the dropdown menu.
Assertion failed: InWorld != nullptr [File:D:\Build\UE4_Main\Engine\Source\Editor\UnrealEd\Private\EditorBrushBuilder.cpp] [Line: 40] UE4Editor_Core!FDebug::AssertFailed() [d:\build\ue4_main\engine\source\runtime\core\private\misc\outputdevice.cpp:413] UE4Editor_UnrealEd!UEditorBrushBuilder::EndBrush() [d:\build\ue4_main\engine\source\editor\unrealed\private\editorbrushbuilder.cpp:41] UE4Editor_UnrealEd!UCubeBuilder::Build() [d:\build\ue4_main\engine\source\editor\unrealed\private\editorbrushbuilder.cpp:491] UE4Editor_DetailCustomizations!`FBrushDetails::CustomizeDetails'::`2'::Local::OnClassPicked() [d:\build\ue4_main\engine\source\editor\detailcustomizations\private\brushdetails.cpp:147] UE4Editor_DetailCustomizations!TBaseStaticDelegateInstance<void __cdecl(UClass * __ptr64),TSharedRef<IPropertyHandle,0>,IDetailLayoutBuilder * __ptr64>::ExecuteIfSafe() [d:\build\ue4_main\engine\source\runtime\core\public\delegates\delegateinstancesimpl.h:1017] UE4Editor_ClassViewer!SClassViewer::OnClassViewerSelectionChanged() [d:\build\ue4_main\engine\source\editor\classviewer\private\sclassviewer.cpp:2197] UE4Editor_ClassViewer!TBaseSPMethodDelegateInstance<0,SClassViewer,0,TTypeWrapper<void> __cdecl(TSharedPtr<FClassViewerNode,0>,enum ESelectInfo::Type)>::Execute() [d:\build\ue4_main\engine\source\runtime\core\public\delegates\delegateinstancesimpl.h:317] UE4Editor_ClassViewer!TBaseSPMethodDelegateInstance<0,SClassViewer,0,void __cdecl(TSharedPtr<FClassViewerNode,0>,enum ESelectInfo::Type)>::ExecuteIfSafe() [d:\build\ue4_main\engine\source\runtime\core\public\delegates\delegateinstancesimpl.h:424] UE4Editor_ClassViewer!TBaseDelegate<void,TSharedPtr<FClassViewerNode,0>,enum ESelectInfo::Type>::ExecuteIfBound() [d:\build\ue4_main\engine\source\runtime\core\public\delegates\delegatesignatureimpl.inl:608] UE4Editor_ClassViewer!SListView<TSharedPtr<FClassViewerNode,0> >::Private_SignalSelectionChanged() [d:\build\ue4_main\engine\source\runtime\slate\public\widgets\views\slistview.h:638] UE4Editor_ClassViewer!STableRow<TSharedPtr<FString,0> >::OnMouseButtonUp() [d:\build\ue4_main\engine\source\runtime\slate\public\widgets\views\stablerow.h:449] UE4Editor_Slate!<lambda_8d0e9a1da76abd0a756a3a9d775f5ed1>::operator()() [d:\build\ue4_main\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:4611] UE4Editor_Slate!FEventRouter::Route<FReply,FEventRouter::FToLeafmostPolicy,FPointerEvent,<lambda_8d0e9a1da76abd0a756a3a9d775f5ed1> >() [d:\build\ue4_main\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:215] UE4Editor_Slate!FSlateApplication::RoutePointerUpEvent() [d:\build\ue4_main\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:4600] UE4Editor_Slate!FSlateApplication::ProcessMouseButtonUpEvent() [d:\build\ue4_main\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:5054] UE4Editor_Slate!FSlateApplication::OnMouseUp() [d:\build\ue4_main\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:5034] UE4Editor_Core!FWindowsApplication::ProcessDeferredMessage() [d:\build\ue4_main\engine\source\runtime\core\private\windows\windowsapplication.cpp:1512] UE4Editor_Core!FWindowsApplication::DeferMessage() [d:\build\ue4_main\engine\source\runtime\core\private\windows\windowsapplication.cpp:1852] UE4Editor_Core!FWindowsApplication::ProcessMessage() [d:\build\ue4_main\engine\source\runtime\core\private\windows\windowsapplication.cpp:747] UE4Editor_Core!FWindowsApplication::AppWndProc() [d:\build\ue4_main\engine\source\runtime\core\private\windows\windowsapplication.cpp:669] user32 user32 UE4Editor_Core!FWindowsPlatformMisc::PumpMessages() [d:\build\ue4_main\engine\source\runtime\core\private\windows\windowsplatformmisc.cpp:905] UE4Editor!FEngineLoop::Tick() [d:\build\ue4_main\engine\source\runtime\launch\private\launchengineloop.cpp:2771] UE4Editor!GuardedMain() [d:\build\ue4_main\engine\source\runtime\launch\private\launch.cpp:156] UE4Editor!GuardedMainWrapper() [d:\build\ue4_main\engine\source\runtime\launch\private\windows\launchwindows.cpp:126] UE4Editor!WinMain() [d:\build\ue4_main\engine\source\runtime\launch\private\windows\launchwindows.cpp:202] UE4Editor!__scrt_common_main_seh() [f:\dd\vctools\crt\vcstartup\src\startup\exe_common.inl:264] kernel32 ntdll
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