[BUG] Child Actor Component Crash

Development Programming & Scripting
1

Hello!

This is a pretty nasty one, but seems to be easily reproducible. I have a character blueprint that is a base for four other character blueprints, I am trying to attach a child actor component in the components tab.

  1. Create a child actor blueprint in the base blueprint. In my case it is parented to another component within that blueprint.
  2. Assign the child blueprint to that component.
  3. Translate the child actor component.
  4. Compile, and crash to desktop. Looks like there’s some confusion as to which components are owned by whom.

Callstack appended below:

Access violation - code c0000005 (first/second chance not available)

UE4Editor_Engine!UActorComponent::GetOwner() + 6 bytes [d:\aitd\digitalconfectioners_tan_luke\ue4\engine\source\runtime\engine\private\actorcomponent.cpp:161]
UE4Editor_UnrealEd!FBlueprintCompileReinstancer::ReplaceInstancesOfClass() + 1289 bytes [d:\aitd\digitalconfectioners_tan_luke\ue4\engine\source\editor\unrealed\private\kismet2\kismetreinstanceutilities.cpp:283]
UE4Editor_UnrealEd!FBlueprintCompileReinstancer::ReinstanceObjects() + 78 bytes [d:\aitd\digitalconfectioners_tan_luke\ue4\engine\source\editor\unrealed\private\kismet2\kismetreinstanceutilities.cpp:164]
UE4Editor_UnrealEd!FKismetEditorUtilities::CompileBlueprint() + 666 bytes [d:\aitd\digitalconfectioners_tan_luke\ue4\engine\source\editor\unrealed\private\kismet2\kismet2.cpp:354]
UE4Editor_Kismet!FBlueprintEditor::Compile() + 560 bytes [d:\aitd\digitalconfectioners_tan_luke\ue4\engine\source\editor\kismet\private\blueprinteditor.cpp:2164]
UE4Editor_Kismet!TBaseSPMethodDelegateInstance_NoParams<FBlueprintEditor,void,0>::Execute() + 45 bytes [d:\aitd\digitalconfectioners_tan_luke\ue4\engine\source\runtime\core\public\templates\delegateinstancesimpl.inl:223]
UE4Editor_Kismet!TBaseSPMethodDelegateInstance_NoParams<FBlueprintEditor,void,0>::ExecuteIfSafe() + 55 bytes [d:\aitd\digitalconfectioners_tan_luke\ue4\engine\source\runtime\core\public\templates\delegateinstancesimpl.inl:250]
UE4Editor_Slate!FUICommandList::ExecuteAction() + 160 bytes [d:\aitd\digitalconfectioners_tan_luke\ue4\engine\source\runtime\slate\private\inputbinding.cpp:782]
UE4Editor_Slate!SToolBarButtonBlock::OnClicked() + 253 bytes [d:\aitd\digitalconfectioners_tan_luke\ue4\engine\source\runtime\slate\private\multibox\stoolbarbuttonblock.cpp:295]
UE4Editor_Slate!TBaseSPMethodDelegateInstance_RetVal_NoParams<SToolBarButtonBlock,FReply,0>::Execute() + 76 bytes [d:\aitd\digitalconfectioners_tan_luke\ue4\engine\source\runtime\core\public\templates\delegateinstancesimpl.inl:223]
UE4Editor_Slate!TBaseDelegate_RetVal_NoParams<FReply>::Execute() + 26 bytes [d:\aitd\digitalconfectioners_tan_luke\ue4\engine\source\runtime\core\public\templates\delegatesignatureimpl.inl:996]
UE4Editor_Slate!SButton::OnMouseButtonUp() + 293 bytes [d:\aitd\digitalconfectioners_tan_luke\ue4\engine\source\runtime\slate\private\sbutton.cpp:178]
UE4Editor_Slate!FSlateApplication::ProcessMouseButtonUpMessage() + 559 bytes [d:\aitd\digitalconfectioners_tan_luke\ue4\engine\source\runtime\slate\private\slateapplication.cpp:3482]
UE4Editor_Slate!FSlateApplication::OnMouseUp() + 528 bytes [d:\aitd\digitalconfectioners_tan_luke\ue4\engine\source\runtime\slate\private\slateapplication.cpp:3450]
UE4Editor_Core!FWindowsApplication::ProcessDeferredMessage() + 2776 bytes [d:\aitd\digitalconfectioners_tan_luke\ue4\engine\source\runtime\core\private\windows\windowsapplication.cpp:1085]
UE4Editor_Core!FWindowsApplication::DeferMessage() + 273 bytes [d:\aitd\digitalconfectioners_tan_luke\ue4\engine\source\runtime\core\private\windows\windowsapplication.cpp:1331]
UE4Editor_Core!FWindowsApplication::ProcessMessage() + 2109 bytes [d:\aitd\digitalconfectioners_tan_luke\ue4\engine\source\runtime\core\private\windows\windowsapplication.cpp:523]
UE4Editor_Core!FWindowsApplication::AppWndProc() + 98 bytes [d:\aitd\digitalconfectioners_tan_luke\ue4\engine\source\runtime\core\private\windows\windowsapplication.cpp:461]
user32 + 105425 bytes
user32 + 104666 bytes
UE4Editor_Core!WinPumpMessages() + 57 bytes [d:\aitd\digitalconfectioners_tan_luke\ue4\engine\source\runtime\core\private\windows\windowsplatformmisc.cpp:581]
UE4Editor_Core!FWindowsPlatformMisc::PumpMessages() + 75 bytes [d:\aitd\digitalconfectioners_tan_luke\ue4\engine\source\runtime\core\private\windows\windowsplatformmisc.cpp:609]
UE4Editor!FEngineLoop::Tick() + 4653 bytes [d:\aitd\digitalconfectioners_tan_luke\ue4\engine\source\runtime\launch\private\launchengineloop.cpp:1941]
UE4Editor!GuardedMain() + 476 bytes [d:\aitd\digitalconfectioners_tan_luke\ue4\engine\source\runtime\launch\private\launch.cpp:132]
UE4Editor!GuardedMainWrapper() + 26 bytes [d:\aitd\digitalconfectioners_tan_luke\ue4\engine\source\runtime\launch\private\windows\launchwindows.cpp:120]
UE4Editor!WinMain() + 249 bytes [d:\aitd\digitalconfectioners_tan_luke\ue4\engine\source\runtime\launch\private\windows\launchwindows.cpp:196]
UE4Editor!__tmainCRTStartup() + 329 bytes [f:\dd\vctools\crt\crtw32\dllstuff\crtexe.c:618]
2

I also found a workaround, though it isn’t a great one.

When you get to step 4, don’t compile, save the blueprint and quit the editor. When you reopen it, it will save just fine.

If you apply a new translation to the child actor component, and try to compile it from there, it will still crash again.

3

Hi ambershee,

Thus far I have been unable to reproduce this effect on my end. Could you post your logs so we can have a look? Thank you!

4

Hi ,

We have not heard from you in quite some time. I am marking this as answered for tracking purposes. If you are still experiencing this crash. Please respond with the requested information. Thank you!

5

The relevant portion of the log has been included below

6

Have you been able to reproduce this effect in a clean project with no additional content?