How to Fix UE5 C2664 Error: Cannot Convert Parameter in C++ Unreal Engine

Why You’re Seeing This Error

You’re passing an argument to a function that doesn’t match the expected parameter type, and the compiler can’t automatically convert between these types.

Example Error Message

C2664: 'void UGameplayStatics::PlaySound2D(const UObject *,USoundBase *,float,float,float,USoundConcurrency *)': cannot convert argument 2 from 'const TCHAR [11]' to 'USoundBase *'

Solution

1. Check parameter types: Make sure you’re passing the correct type of argument.

// Incorrect
UGameplayStatics::PlaySound2D(this, TEXT("Explosion"));

// Correct
USoundBase* ExplosionSound = LoadObject<USoundBase>(nullptr, TEXT("/Game/Sounds/Explosion"));
UGameplayStatics::PlaySound2D(this, ExplosionSound);

2. Use proper casting: Use appropriate casting functions when needed.

// Use Cast<> for UObject types
AMyActor* MyActor = Cast<AMyActor>(ActorReference);

// Use static_cast, reinterpret_cast, or other C++ casts as appropriate
float Value = static_cast<float>(IntValue);

3. Load assets correctly: Make sure you’re loading and referencing assets correctly.

cppCopy// Load assets using proper references
static ConstructorHelpers::FObjectFinder<UStaticMesh> MeshAsset(TEXT("/Game/Meshes/MyMesh"));
if (MeshAsset.Succeeded())
{
    StaticMeshComponent->SetStaticMesh(MeshAsset.Object);
}