Nullptr when trying to cast UAnimInstance to custom object

[Belgathorn]

I’m following a tutorial from a book, I just finished setting up animations for the player character, but I have problems with the code from the book; It wont work!

It says in the book

void APlayerAvatar::Tick(float DeltaTime)
{
	Super::Tick(DeltaTime);

	UPlayerAvatarAnimInstance* animInst = Cast<UPlayerAvatarAnimInstance>(GetMesh()->GetAnimInstance());
	animInst->Speed = GetCharacterMovement()->Velocity.Size2D();

}

It compiles, and builds with no errors. But when I enter playtest mode in the editor it crashes whereas an ‘unreal crash’ window comes up. The debug tells me that there is a write access violation because animInst was nullptr.

I tried:

auto animInst = Cast<UPlayerAvatarAnimInstance>(GetMesh()->GetAnimInstance());
	animInst->Speed = GetCharacterMovement()->Velocity.Size2D();

and also this:

UAnimInstance* temp = GetMesh()->GetAnimInstance();
UPlayerAvatarAnimInstance* animInst = Cast<UPlayerAvatarAnimInstance>(temp);
animInst->Speed = GetCharacterMovement()->Velocity.Size2D();

But same thing happens.
I understand why I cant do anything with a nullptr, but unsure why it happens.
I’ll try to solve this, but any kind of help is appreciated.

Version of the engine is 5.2.1

Thanks!

[Belgathorn]

I’ve solved it myself. It turned out I missed out on one important step which was to set my playeravatar blueprint to use the animation blueprint.