Class which was marked abstract was trying to be loaded.

Development Programming & Scripting C++
1

Hi everyone! I wrote simple code:

.h



class HORRORGAME_API AScreamSystem : public ACharacter
{
	GENERATED_UCLASS_BODY()

	UPROPERTY(VisibleAnywhere, BlueprintReadOnly, Category=MeshTrigger)
    TSubobjectPtr<class UMeshComponent> meshTrigger;

	void Tick(float DeltaSeconds);
};

.cpp



AScreamSystem::AScreamSystem(const class FPostConstructInitializeProperties& PCIP)
	: Super(PCIP)
{
	meshTrigger = PCIP.CreateDefaultSubobject<UMeshComponent>(this, TEXT("Mesh"));
}


void AScreamSystem::Tick(float DeltaSeconds)
{
	GEngine->AddOnScreenDebugMessage(1, 10, FColor::Green, "Hello, world");
}

I don’t have errors but Visual Studio doesn’t compiles it

In log:
Class which was marked abstract was trying to be loaded. It will be nulled out on save. Mesh MeshComponent

What should I do?

2

UMeshComponent is an abstract class - see the documentationand you will see it starts with UCLASS(Abstract).

This means you must first create a subclass of UMeshComponent and use that as your meshTrigger.

3

Please write me example

4

UMeshComponent is abstract class, which cannot be instantiated, so you need to create derived class instead, which itself is not abstract:

As an example:


meshTrigger = PCIP.CreateDefaultSubobject<USkeletalMeshComponent>(this, TEXT("MESH"));

You can see all derived classes in documentation. :slight_smile:

6

Thank you!