Crash with Slate Widget

[livelyeko]

Recently got into learning how to use Slate Widget.

I was trying to initialize the Slate Widget when pressing “B” but upon pressing the editor crashes on the line:

BuilderInventoryWidget = SNew(SBuilderInventoryWidget).OwningHUD(this);

Here’s the code in the CPP file for when I call the function.

void ABuilderInventoryHUD::SetBuilderInventoryHUD()
{
	if(GEngine && GEngine->GameViewport)
	{
		BuilderInventoryWidget = SNew(SBuilderInventoryWidget).OwningHUD(this);
		GEngine->GameViewport->AddViewportWidgetContent(SAssignNew(BuilderInventoryWidgetContainer, SWeakWidget).PossiblyNullContent(BuilderInventoryWidget.ToSharedRef()));
	}
}

Here’s the Slate Widget I want to set:

// Fill out your copyright notice in the Description page of Project Settings.

#pragma once

#include "CoreMinimal.h"
#include "SlateBasics.h"
#include "SlateExtras.h"

/**
 * 
 */
class SBuilderInventoryWidget : public SCompoundWidget
{
public:
	SLATE_BEGIN_ARGS(SBuilderInventoryWidget) {}
	SLATE_ARGUMENT(TWeakObjectPtr<class ABuilderInventoryHUD>, OwningHUD)
	SLATE_END_ARGS()

	void Construct(const FArguments& InArgs);
	
	TWeakObjectPtr<class ABuilderInventoryHUD> OwningHUD;

	virtual bool SupportsKeyboardFocus() const override { return true; };

	
};

I also added the private dependency modules “Slate” and “SlateCore”

My guess is that I’m initializing SBuilderInventoryWidget wrong somehow, but I’m not too sure how to fix this. Thanks in advance :))

[Hexavx]

Do not use smart pointer on UObject, it already has its own lifecycle manager.
If it still crashing, please post the crash message.

[livelyeko]

Hey! sorry for the late reply. For the smart pointers, I just deleted the TWeakPtr variable and all references to it. Hopefully I did that part correctly.

Here’s the widget h file:

class SBuilderInventoryWidget : public SCompoundWidget
{
public:
	SLATE_BEGIN_ARGS(SBuilderInventoryWidget) {}
	SLATE_END_ARGS()

	void Construct(const FArguments& InArgs);

	virtual bool SupportsKeyboardFocus() const override { return true; };

	
};

Here’s the function creating the widget.

void ABuilderInventoryHUD::SetBuilderInventoryHUD()
{
	if(GEngine && GEngine->GameViewport)
	{
		BuilderInventoryWidget = SNew(SBuilderInventoryWidget);
		GEngine->GameViewport->AddViewportWidgetContent(SAssignNew(BuilderInventoryWidgetContainer, SWeakWidget).PossiblyNullContent(BuilderInventoryWidget.ToSharedRef()));
	}
}

Unfortunately it still crashed.

I’m not too sure how to post the crash report properly so I just copy and pasted.
Here it is:

Unhandled Exception: EXCEPTION_ACCESS_VIOLATION writing address 0x00000000000004f0

UnrealEditor_MyProject2!ABuilderInventoryHUD::SetBuilderInventoryHUD() [D:\Projects\Unreal Projects\MyProject2\Source\MyProject2\BuilderInventoryHUD.cpp:18]
UnrealEditor_MyProject2!ACPP_PlayerBase::BuildMode() [D:\Projects\Unreal Projects\MyProject2\Source\MyProject2\CPP_PlayerBase.cpp:950]
UnrealEditor_MyProject2!TBaseUObjectMethodDelegateInstance<0,ACPP_PlayerBase,void __cdecl(void),FDefaultDelegateUserPolicy>::Execute() [D:\InstalledPrograms\UE_5.2\Engine\Source\Runtime\Core\Public\Delegates\DelegateInstancesImpl.h:535]
UnrealEditor_EnhancedInput!UEnhancedPlayerInput::ProcessInputStack() [D:\build\++UE5\Sync\Engine\Plugins\EnhancedInput\Source\EnhancedInput\Private\EnhancedPlayerInput.cpp:490]
UnrealEditor_Engine!APlayerController::ProcessPlayerInput() [D:\build\++UE5\Sync\Engine\Source\Runtime\Engine\Private\PlayerController.cpp:2704]
UnrealEditor_Engine!APlayerController::TickPlayerInput() [D:\build\++UE5\Sync\Engine\Source\Runtime\Engine\Private\PlayerController.cpp:4985]
UnrealEditor_Engine!APlayerController::PlayerTick() [D:\build\++UE5\Sync\Engine\Source\Runtime\Engine\Private\PlayerController.cpp:2308]
UnrealEditor_Engine!APlayerController::TickActor() [D:\build\++UE5\Sync\Engine\Source\Runtime\Engine\Private\PlayerController.cpp:5137]
UnrealEditor_Engine!FActorTickFunction::ExecuteTick() [D:\build\++UE5\Sync\Engine\Source\Runtime\Engine\Private\Actor.cpp:212]
UnrealEditor_Engine!FTickFunctionTask::DoTask() [D:\build\++UE5\Sync\Engine\Source\Runtime\Engine\Private\TickTaskManager.cpp:275]
UnrealEditor_Engine!TGraphTask<FTickFunctionTask>::ExecuteTask() [D:\build\++UE5\Sync\Engine\Source\Runtime\Core\Public\Async\TaskGraphInterfaces.h:1310]
UnrealEditor_Core!FNamedTaskThread::ProcessTasksNamedThread() [D:\build\++UE5\Sync\Engine\Source\Runtime\Core\Private\Async\TaskGraph.cpp:758]
UnrealEditor_Core!FNamedTaskThread::ProcessTasksUntilQuit() [D:\build\++UE5\Sync\Engine\Source\Runtime\Core\Private\Async\TaskGraph.cpp:649]
UnrealEditor_Core!FTaskGraphCompatibilityImplementation::WaitUntilTasksComplete() [D:\build\++UE5\Sync\Engine\Source\Runtime\Core\Private\Async\TaskGraph.cpp:2123]
UnrealEditor_Engine!FTickTaskSequencer::ReleaseTickGroup() [D:\build\++UE5\Sync\Engine\Source\Runtime\Engine\Private\TickTaskManager.cpp:556]
UnrealEditor_Engine!FTickTaskManager::RunTickGroup() [D:\build\++UE5\Sync\Engine\Source\Runtime\Engine\Private\TickTaskManager.cpp:1583]
UnrealEditor_Engine!UWorld::RunTickGroup() [D:\build\++UE5\Sync\Engine\Source\Runtime\Engine\Private\LevelTick.cpp:770]
UnrealEditor_Engine!UWorld::Tick() [D:\build\++UE5\Sync\Engine\Source\Runtime\Engine\Private\LevelTick.cpp:1512]
UnrealEditor_UnrealEd!UEditorEngine::Tick() [D:\build\++UE5\Sync\Engine\Source\Editor\UnrealEd\Private\EditorEngine.cpp:1905]
UnrealEditor_UnrealEd!UUnrealEdEngine::Tick() [D:\build\++UE5\Sync\Engine\Source\Editor\UnrealEd\Private\UnrealEdEngine.cpp:519]
UnrealEditor!FEngineLoop::Tick() [D:\build\++UE5\Sync\Engine\Source\Runtime\Launch\Private\LaunchEngineLoop.cpp:5812]
UnrealEditor!GuardedMain() [D:\build\++UE5\Sync\Engine\Source\Runtime\Launch\Private\Launch.cpp:188]
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:284]
UnrealEditor!__scrt_common_main_seh() [D:\a\_work\1\s\src\vctools\crt\vcstartup\src\startup\exe_common.inl:288]
kernel32
ntdll

[Hexavx]

looks like u are calling a function from a null pointer
it could be at here BuilderInventoryHUD.cpp:18

[livelyeko]

Yeah I figured that it was a null pointer. Couldn’t figure it out though so at the moment I’m just going to go back to UMG and try figuring out Slate later. Thanks for the help though :))