This is a trending crash coming out of the 4.18 release, and may be a regression. Users have not provided any descriptions of their actions when the crash occurred.
Source Context
361 // "Normal" menus are created and managed by the application's menu stack functions 362 if (bUseApplicationMenuStack) 363 { 364 if (MethodInUse.GetPopupMethod() == EPopupMethod::CreateNewWindow) 365 { 366 // Open the pop-up 367 TSharedPtr<IMenu> NewMenu = FSlateApplication::Get().PushMenu(AsShared(), MyWidgetPath, MenuContentRef, NewPosition, TransitionEffect, bFocusMenu, MyGeometry.GetLocalSize(), MethodInUse.GetPopupMethod(), bIsCollapsedByParent); 368 369 PopupMenuPtr = NewMenu; 370 check(NewMenu.IsValid() && NewMenu->GetOwnedWindow().IsValid()); 371 ***** NewMenu->GetOnMenuDismissed().AddSP(this, &SMenuAnchor::OnMenuClosed); 372 PopupWindowPtr = NewMenu->GetOwnedWindow(); 373 } 374 else 375 { 376 // We are re-using the current window instead of creating a new one. 377 // The popup will be presented as a child of this widget. 378 ensure(MethodInUse.GetPopupMethod() == EPopupMethod::UseCurrentWindow); 379 PopupWindowPtr = MyWidgetPath.GetWindow(); 380 381 if (bFocusMenu) 382 { 383 FSlateApplication::Get().ReleaseMouseCaptureForUser(FocusUserIndex); 384 } 385 386 TSharedRef<SMenuAnchor> SharedThis = StaticCastSharedRef<SMenuAnchor>(AsShared());
repro steps currently unknown
Assertion failed: NewMenu.IsValid() && NewMenu->GetOwnedWindow().IsValid() [File:D:\Build\++UE4+Release-4.18+Compile\Sync\Engine\Source\Runtime\Slate\Private\Widgets\Input\SMenuAnchor.cpp] [Line: 371] UE4Editor_Slate!SMenuAnchor::SetIsOpen() [smenuanchor.cpp:372] UE4Editor_Slate!SComboButton::OnButtonClicked() [scombobutton.cpp:86] UE4Editor_Slate!TMemberFunctionCaller<SComboButton,FReply() [delegateinstanceinterface.h:165] UE4Editor_Slate!UE4Tuple_Private::TTupleImpl<TIntegerSequence<unsigned int> >::ApplyAfter<TMemberFunctionCaller<SComboButton,FReply() [tuple.h:497] UE4Editor_Slate!TBaseSPMethodDelegateInstance<0,SComboButton,0,FReply __cdecl() [delegateinstancesimpl.h:327] UE4Editor_Slate!TBaseDelegate<FReply>::Execute() [delegatesignatureimpl.inl:537] UE4Editor_Slate!SButton::OnMouseButtonDown() [sbutton.cpp:215] UE4Editor_Slate!<lambda_7097b900f0e4be30d80fb18f98c51ea0>::operator() [slateapplication.cpp:5171] UE4Editor_Slate!FEventRouter::Route<FReply,FEventRouter::FBubblePolicy,FPointerEvent,<lambda_7097b900f0e4be30d80fb18f98c51ea0> >() [slateapplication.cpp:234] UE4Editor_Slate!FSlateApplication::RoutePointerDownEvent() [slateapplication.cpp:5160] UE4Editor_Slate!FSlateApplication::ProcessMouseButtonDownEvent() [slateapplication.cpp:5113] UE4Editor_Slate!FSlateApplication::OnMouseDown() [slateapplication.cpp:5031] UE4Editor_ApplicationCore!FWindowsApplication::ProcessDeferredMessage() [windowsapplication.cpp:1733] UE4Editor_ApplicationCore!FWindowsApplication::DeferMessage() [windowsapplication.cpp:2171] UE4Editor_ApplicationCore!FWindowsApplication::ProcessMessage() [windowsapplication.cpp:888] UE4Editor_ApplicationCore!FWindowsApplication::AppWndProc() [windowsapplication.cpp:725] user32!UserCallWinProcCheckWow() user32!DispatchMessageWorker() UE4Editor_ApplicationCore!FWindowsPlatformApplicationMisc::PumpMessages() [windowsplatformapplicationmisc.cpp:129] UE4Editor!FEngineLoop::Tick() [launchengineloop.cpp:3220] 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()
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-51922 in the post.