Unreal Engine Issues and Bug Tracker (UE-173759)

Description

Reproduced 3/3 times, issue does not occur in //UE5/Release-5.0 - CL 20979098 Binary. Confirmed Regression.

Seems to work fine when compiled once, but after the 2nd or 3rd time it crashes.

Steps to Reproduce

Create the Third Person Template Project.
Create new c++ class. Parent class is Animinstance.
Add custom AnimInstanceProxy, CreateAnimInstanceProxy override, DestroyAnimInstanceProxy override and NativeInitializeAnimation

 // MyAnimInstance.h ----------------------------------------------------------------------------------------------
#pragma once

#include "CoreMinimal.h"
#include "Animation/AnimInstance.h"
#include "Animation/AnimInstanceProxy.h"
#include "MyAnimInstance.generated.h"

USTRUCT(BlueprintType)
struct FTestKAnimInstanceProxy : public FAnimInstanceProxy
{

GENERATED_BODY()

virtual void PreUpdate(UAnimInstance* Instance, float DeltaSeconds) override;
// virtual void Update(float DeltaSeconds) override;
};

/**
*
*/
UCLASS()
class BUGREPORT01_API UMyAnimInstance : public UAnimInstance
{
GENERATED_BODY()

protected:

UPROPERTY(Transient, BlueprintReadOnly, Category = "Example", meta = (AllowPrivateAccess = "true"))
FTestKAnimInstanceProxy Proxy;

virtual FTestKAnimInstanceProxy* CreateAnimInstanceProxy() override
{
return &Proxy;
}
virtual void DestroyAnimInstanceProxy(FAnimInstanceProxy* InProxy) override
{
}

public:
virtual void NativeInitializeAnimation() override;
};
// MyAnimInstance.cpp ----------------------------
#include "MyAnimInstance.h"

void FTestKAnimInstanceProxy::PreUpdate(UAnimInstance* Instance, float DeltaSeconds)
{
Super::PreUpdate(Instance, DeltaSeconds);
}

void UMyAnimInstance::NativeInitializeAnimation()
{
}
//-----------------------------------------------

Save & Compile.
Create animation blueprint and select 'Template'. Parent class is 'Animinstance'. This file call 'ABPT_test
Connect the 'Blend Pose by bool' node to the output pose
Connect the node's inputs to a "Input Pose" node & "Sequence Player" node
In Details, publish the Sequence variable of Sequence Player, then expose pin as a variable. Compile
Open Contents/Characters/Mannequins/Animations/ABP_Manny
Change the parent class of ABP_Manny to MyAniminstance(created above). Link ABPT_test between 'control rig output' and 'output pose' and sequence.
Hit the Compile button 2-3 times

Actual Result: Editor crashes

Expected Result: Editor does not crash

Callstack

Assertion failed: AnimBlueprintClass [File:D:\build\++UE5\Sync\Engine\Source\Runtime\Engine\Private\Animation\AnimNodeBase.cpp] [Line: 199]
 
UnrealEditor_Engine!FPoseLinkBase::AttemptRelink() [D:\build\++UE5\Sync\Engine\Source\Runtime\Engine\Private\Animation\AnimNodeBase.cpp:199]
UnrealEditor_Engine!FAnimNode_LinkedAnimGraph::DynamicLink() [D:\build\++UE5\Sync\Engine\Source\Runtime\Engine\Private\Animation\AnimNode_LinkedAnimGraph.cpp:365]
UnrealEditor_Engine!FAnimNode_LinkedAnimGraph::HandleObjectsReinstanced_Impl() [D:\build\++UE5\Sync\Engine\Source\Runtime\Engine\Private\Animation\AnimNode_LinkedAnimGraph.cpp:492]
UnrealEditor_Engine!FAnimNode_CustomProperty::HandleObjectsReinstanced() [D:\build\++UE5\Sync\Engine\Source\Runtime\Engine\Private\Animation\AnimNode_CustomProperty.cpp:132]
UnrealEditor_Engine!TBaseRawMethodDelegateInstance<0,FAnimNode_CustomProperty,void __cdecl(TMap<UObject *,UObject *,FDefaultSetAllocator,TDefaultMapHashableKeyFuncs<UObject *,UObject *,0> > const &),FDefaultDelegateUserPolicy>::ExecuteIfSafe() [D:\build\++UE5\Sync\Engine\Source\Runtime\Core\Public\Delegates\DelegateInstancesImpl.h:476]
UnrealEditor_UnrealEd!FBlueprintCompileReinstancer::ReplaceInstancesOfClass_Inner() [D:\build\++UE5\Sync\Engine\Source\Editor\UnrealEd\Private\Kismet2\KismetReinstanceUtilities.cpp:2510]
UnrealEditor_UnrealEd!FBlueprintCompileReinstancer::BatchReplaceInstancesOfClass() [D:\build\++UE5\Sync\Engine\Source\Editor\UnrealEd\Private\Kismet2\KismetReinstanceUtilities.cpp:1622]
UnrealEditor_Kismet!FBlueprintCompilationManagerImpl::FlushReinstancingQueueImpl() [D:\build\++UE5\Sync\Engine\Source\Editor\Kismet\Private\BlueprintCompilationManager.cpp:1796]
UnrealEditor_Kismet!FBlueprintCompilationManagerImpl::CompileSynchronouslyImpl() [D:\build\++UE5\Sync\Engine\Source\Editor\Kismet\Private\BlueprintCompilationManager.cpp:271]
UnrealEditor_Kismet!FBlueprintCompilationManager::CompileSynchronously() [D:\build\++UE5\Sync\Engine\Source\Editor\Kismet\Private\BlueprintCompilationManager.cpp:3294]
UnrealEditor_UnrealEd!FKismetEditorUtilities::CompileBlueprint() [D:\build\++UE5\Sync\Engine\Source\Editor\UnrealEd\Private\Kismet2\Kismet2.cpp:763]
UnrealEditor_Kismet!FBlueprintEditor::Compile() [D:\build\++UE5\Sync\Engine\Source\Editor\Kismet\Private\BlueprintEditor.cpp:4060]
UnrealEditor_Kismet!TBaseSPMethodDelegateInstance<0,FBlueprintEditor,1,void __cdecl(void),FDefaultDelegateUserPolicy>::ExecuteIfSafe() [D:\build\++UE5\Sync\Engine\Source\Runtime\Core\Public\Delegates\DelegateInstancesImpl.h:312]
UnrealEditor_Slate!FUICommandList::ExecuteAction() [D:\build\++UE5\Sync\Engine\Source\Runtime\Slate\Private\Framework\Commands\UICommandList.cpp:111]
UnrealEditor_Slate!SToolBarButtonBlock::OnClicked() [D:\build\++UE5\Sync\Engine\Source\Runtime\Slate\Private\Framework\MultiBox\SToolBarButtonBlock.cpp:384]
UnrealEditor_Slate!TBaseSPMethodDelegateInstance<0,SToolBarButtonBlock,1,FReply __cdecl(void),FDefaultDelegateUserPolicy>::Execute() [D:\build\++UE5\Sync\Engine\Source\Runtime\Core\Public\Delegates\DelegateInstancesImpl.h:295]
UnrealEditor_Slate!SButton::ExecuteOnClick() [D:\build\++UE5\Sync\Engine\Source\Runtime\Slate\Private\Widgets\Input\SButton.cpp:465]
UnrealEditor_Slate!SButton::OnMouseButtonUp() [D:\build\++UE5\Sync\Engine\Source\Runtime\Slate\Private\Widgets\Input\SButton.cpp:390]
UnrealEditor_Slate!<lambda_51e270ca99ea7ce852539efd04dd453f>::operator()() [D:\build\++UE5\Sync\Engine\Source\Runtime\Slate\Private\Framework\Application\SlateApplication.cpp:5046]
UnrealEditor_Slate!FEventRouter::Route<FReply,FEventRouter::FToLeafmostPolicy,FPointerEvent,<lambda_51e270ca99ea7ce852539efd04dd453f> >() [D:\build\++UE5\Sync\Engine\Source\Runtime\Slate\Private\Framework\Application\SlateApplication.cpp:412]
UnrealEditor_Slate!FSlateApplication::RoutePointerUpEvent() [D:\build\++UE5\Sync\Engine\Source\Runtime\Slate\Private\Framework\Application\SlateApplication.cpp:5032]
UnrealEditor_Slate!FSlateApplication::ProcessMouseButtonUpEvent() [D:\build\++UE5\Sync\Engine\Source\Runtime\Slate\Private\Framework\Application\SlateApplication.cpp:5601]
UnrealEditor_Slate!FSlateApplication::OnMouseUp() [D:\build\++UE5\Sync\Engine\Source\Runtime\Slate\Private\Framework\Application\SlateApplication.cpp:5566]
UnrealEditor_ApplicationCore!FWindowsApplication::ProcessDeferredMessage() [D:\build\++UE5\Sync\Engine\Source\Runtime\ApplicationCore\Private\Windows\WindowsApplication.cpp:2219]
UnrealEditor_ApplicationCore!FWindowsApplication::DeferMessage() [D:\build\++UE5\Sync\Engine\Source\Runtime\ApplicationCore\Private\Windows\WindowsApplication.cpp:2726]
UnrealEditor_ApplicationCore!FWindowsApplication::ProcessMessage() [D:\build\++UE5\Sync\Engine\Source\Runtime\ApplicationCore\Private\Windows\WindowsApplication.cpp:1895]
UnrealEditor_ApplicationCore!FWindowsApplication::AppWndProc() [D:\build\++UE5\Sync\Engine\Source\Runtime\ApplicationCore\Private\Windows\WindowsApplication.cpp:925]
user32
user32
InkObj
atlthunk
user32
user32
UnrealEditor_ApplicationCore!FWindowsPlatformApplicationMisc::PumpMessages() [D:\build\++UE5\Sync\Engine\Source\Runtime\ApplicationCore\Private\Windows\WindowsPlatformApplicationMisc.cpp:142]
UnrealEditor!FEngineLoop::Tick() [D:\build\++UE5\Sync\Engine\Source\Runtime\Launch\Private\LaunchEngineLoop.cpp:5291]
UnrealEditor!GuardedMain() [D:\build\++UE5\Sync\Engine\Source\Runtime\Launch\Private\Launch.cpp:202]
UnrealEditor!GuardedMainWrapper() [D:\build\++UE5\Sync\Engine\Source\Runtime\Launch\Private\Windows\LaunchWindows.cpp:107]
UnrealEditor!LaunchWindowsStartup() [D:\build\++UE5\Sync\Engine\Source\Runtime\Launch\Private\Windows\LaunchWindows.cpp:244]
UnrealEditor!WinMain() [D:\build\++UE5\Sync\Engine\Source\Runtime\Launch\Private\Windows\LaunchWindows.cpp:282]
UnrealEditor!__scrt_common_main_seh() [D:\a\_work\1\s\src\vctools\crt\vcstartup\src\startup\exe_common.inl:288]
kernel32
ntdll

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Fixed

Component	UE - Anim - Runtime - Anim Blueprints
Affects Versions	5.1
Target Fix	5.2

Fix Commit	24671407
Main Commit	24672202
Release Commit	24671407

Created	Jan 10, 2023
Resolved	Mar 17, 2023
Updated	Apr 29, 2023

UE-173759

Editor sometimes crashes when trying to compile an Animation Blueprint that extends a class with AnimInstanceProxy

Editor sometimes crashes when trying to compile an Animation Blueprint that extends a class with AnimInstanceProxy

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