Description

[Edit]: This should no longer be a crash as of 4.19.2 - we should only get ensure() reports with this callstack.
=====
This is a common crash coming out of 4.18. Users have not provided any descriptions of their actions when the crash occurred.

Source Context

 835       				// Set the selected child node as the new root
  836       				check(ChildToPromote != nullptr);
  837       				Owner->SetRootComponent(ChildToPromote);
  838       			}
  839       			else    // ...not the root node, so we'll promote the selected child node to this position in its AttachParent's child array.
  840       			{
  841       				// Cache our AttachParent
  842       				USceneComponent* CachedAttachParent = GetAttachParent();
  843       				check(CachedAttachParent != nullptr);
  844       
  845       				// Find the our position in its AttachParent's child array
  846 ***** 				const TArray<USceneComponent*>& AttachSiblings = CachedAttachParent->GetAttachChildren();
  847       				int32 Index = AttachSiblings.Find(this);
  848       				check(Index != INDEX_NONE);
  849       
Steps to Reproduce
  1. Open QAGame in editor.
  2. Add an Empty Actor to the level.
  3. In the Actor's Details, add a Spline Mesh Component.
    • You'll get a warning about the attachment not being made.
  4. Delete the Spline Mesh Component.

RESULT

Ensure.

Callstack
Assertion failed: CachedAttachParent != nullptr [File:D:\Build\++UE4+Release-4.18+Compile\Sync\Engine\Source\Runtime\Engine\Private\Components\SceneComponent.cpp] [Line: 844]

UE4Editor_Engine!USceneComponent::DestroyComponent() [scenecomponent.cpp:847]
UE4Editor_UnrealEd!FComponentEditorUtils::DeleteComponents() [componenteditorutils.cpp:572]
UE4Editor_Kismet!SSCSEditor::OnDeleteNodes() [sscseditor.cpp:5611]
UE4Editor_Kismet!TBaseSPMethodDelegateInstance<0,SSCSEditor,0,TTypeWrapper<void> __cdecl() [delegateinstancesimpl.h:327]
UE4Editor_Kismet!TBaseSPMethodDelegateInstance<0,SSCSEditor,0,void __cdecl() [delegateinstancesimpl.h:434]
UE4Editor_Slate!FUICommandList::ConditionalProcessCommandBindings() [uicommandlist.cpp:216]
UE4Editor_Slate!FUICommandList::ProcessCommandBindings() [uicommandlist.cpp:160]
UE4Editor_Kismet!SSCSEditor::OnKeyDown() [sscseditor.cpp:3786]
UE4Editor_Slate!<lambda_2afcd964c763e269e2d1a63f3a72f846>::operator() [slateapplication.cpp:4834]
UE4Editor_Slate!FEventRouter::Route<FReply,FEventRouter::FBubblePolicy,FKeyEvent,<lambda_2afcd964c763e269e2d1a63f3a72f846> >() [slateapplication.cpp:234]
UE4Editor_Slate!FEventRouter::RouteAlongFocusPath<FEventRouter::FBubblePolicy,<lambda_2afcd964c763e269e2d1a63f3a72f846>,FKeyEvent>() [slateapplication.cpp:216]
UE4Editor_Slate!FSlateApplication::ProcessKeyDownEvent() [slateapplication.cpp:4832]
UE4Editor_Slate!FSlateApplication::OnKeyDown() [slateapplication.cpp:4744]
UE4Editor_ApplicationCore!FWindowsApplication::ProcessDeferredMessage() [windowsapplication.cpp:1560]
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()

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Fixed
ComponentUE - Gameplay - Components
Affects Versions4.184.19
Target Fix4.25
Fix Commit12295175
Main Commit12296559
Release Commit12295175
CreatedDec 1, 2017
ResolvedMar 19, 2020
UpdatedJul 30, 2020
View Jira Issue