REGRESSION: Can be certain as this testing was blocked by [Link Removed]
Through a specific chain of events (see repro), it's possible to have a non-actor as the value for an Actor Class Reference, and there is no error indicating that this isn't valid, nor is the field cleared.
Once it's in this state, performing some actions can cause a crash (see callstack).
RESULT
Note that 256Cube is accepted as the Default Value with no error. A few actions can result in a crash, such as:
Assertion failed: ObjectA == nullptr || ObjectA->IsA<UClass>() [File:D:\Build\++UE4+Release-4.18+Compile\Sync\Engine\Source\Runtime\CoreUObject\Private\UObject\PropertyClass.cpp] [Line: 156] UE4Editor_CoreUObject!UClassProperty::Identical() propertyclass.cpp:157 UE4Editor_CoreUObject!UStruct::SerializeTaggedProperties() class.cpp:1122 UE4Editor_CoreUObject!UObject::SerializeScriptProperties() obj.cpp:1276 UE4Editor_CoreUObject!UObject::Serialize() obj.cpp:1210 UE4Editor_Engine!AActor::Serialize() actor.cpp:559 UE4Editor_Engine!FCPFUOWriter::FCPFUOWriter() unrealengine.cpp:11900 UE4Editor_Engine!UEngine::CopyPropertiesForUnrelatedObjects() unrealengine.cpp:12009 UE4Editor_UnrealEd!ReplaceActorHelper() kismetreinstanceutilities.cpp:1776 UE4Editor_UnrealEd!FBlueprintCompileReinstancer::ReplaceInstancesOfClass_Inner() kismetreinstanceutilities.cpp:1969 UE4Editor_UnrealEd!FBlueprintCompileReinstancer::BatchReplaceInstancesOfClass() kismetreinstanceutilities.cpp:1474 UE4Editor_Kismet!FBlueprintCompilationManagerImpl::FlushReinstancingQueueImpl() blueprintcompilationmanager.cpp:1041 UE4Editor_Kismet!FBlueprintCompilationManagerImpl::CompileSynchronouslyImpl() blueprintcompilationmanager.cpp:200 UE4Editor_UnrealEd!FKismetEditorUtilities::CompileBlueprint() kismet2.cpp:745 UE4Editor_Kismet!FBlueprintEditor::Compile() blueprinteditor.cpp:3181 UE4Editor_Kismet!TBaseSPMethodDelegateInstance<0,FBlueprintEditor,0,TTypeWrapper<void> __cdecl() delegateinstancesimpl.h:327 UE4Editor_Kismet!TBaseSPMethodDelegateInstance<0,FBlueprintEditor,0,void __cdecl() delegateinstancesimpl.h:434 UE4Editor_Slate!FUICommandList::ExecuteAction() uicommandlist.cpp:97 UE4Editor_Slate!SToolBarButtonBlock::OnClicked() stoolbarbuttonblock.cpp:300 UE4Editor_Slate!TMemberFunctionCaller<SToolBarButtonBlock,FReply() delegateinstanceinterface.h:165 UE4Editor_Slate!UE4Tuple_Private::TTupleImpl<TIntegerSequence<unsigned int> >::ApplyAfter<TMemberFunctionCaller<SToolBarButtonBlock,FReply() tuple.h:497 UE4Editor_Slate!TBaseSPMethodDelegateInstance<0,SToolBarButtonBlock,0,FReply __cdecl() delegateinstancesimpl.h:327 UE4Editor_Slate!TBaseDelegate<FReply>::Execute() delegatesignatureimpl.inl:537 UE4Editor_Slate!SButton::OnMouseButtonUp() sbutton.cpp:282 UE4Editor_Slate!<lambda_1002768c627006711ef2f351a87ec0e7>::operator() slateapplication.cpp:5263 UE4Editor_Slate!FEventRouter::Route<FReply,FEventRouter::FToLeafmostPolicy,FPointerEvent,<lambda_1002768c627006711ef2f351a87ec0e7> >() slateapplication.cpp:234 UE4Editor_Slate!FSlateApplication::RoutePointerUpEvent() slateapplication.cpp:5252 UE4Editor_Slate!FSlateApplication::ProcessMouseButtonUpEvent() slateapplication.cpp:5750 UE4Editor_Slate!FSlateApplication::OnMouseUp() slateapplication.cpp:5730 UE4Editor_ApplicationCore!FWindowsApplication::ProcessDeferredMessage() windowsapplication.cpp:1725 UE4Editor_ApplicationCore!FWindowsApplication::DeferMessage() windowsapplication.cpp:2171 UE4Editor_ApplicationCore!FWindowsApplication::ProcessMessage() windowsapplication.cpp:888 UE4Editor_ApplicationCore!FWindowsApplication::AppWndProc() windowsapplication.cpp:725 user32!<Unknown> user32!<Unknown> 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!<Unknown> ntdll!<Unknown>
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-50764 in the post.
| 0 |
| Component | UE - Gameplay - Blueprint |
|---|---|
| Affects Versions | 4.18 |
| Target Fix | 4.18 |
| Created | Oct 4, 2017 |
|---|---|
| Resolved | Oct 4, 2017 |
| Updated | Apr 27, 2018 |