Hey, bit of a head scratcher for me. I’m following the Ultimate UE5 C++ course on Udemy. I’m doing “Simple Shooter” project from it.
We did some basic stuff, which I (think I) 100% understand:
1 - Created a new C++ class called Gun (from Actor)
2 - Derived a Blueprint class called BP_Gun from it
3 - Assigned 2 components to the constructor so that they show up in the derived BP class.
NOTHING else has been done to the Gun class except these changes:
Gun.h:
private:
UPROPERTY(VisibleAnywhere, Category = "Components")
USceneComponent* Root;
UPROPERTY(VisibleAnywhere, Category = "Components")
USkeletalMeshComponent* Mesh;
Gun.cpp:
AGun::AGun()
{
PrimaryActorTick.bCanEverTick = true;
Root = CreateDefaultSubobject<USceneComponent>(TEXT("Mesh"));
SetRootComponent(Root);
Mesh = CreateDefaultSubobject<USkeletalMeshComponent>(TEXT("Mesh"));
Mesh->SetupAttachment(Root);
}
…and yet when I try to open BP_Gun, I get an error like this: “Default subobject SkeletalMeshComponent Mesh already exists for Gun /Script/SimpleShooter.Default__Gun.”
I tried:
1 - Deleting Intermediate and Binaries folders from the project folder, rebuilding - no success
2 - Step 1 + deleting the temp folders from AppData/Local as well - no success
3 - Switching SkeletalMeshComponent to UStaticMeshComponent - interestingly, I get the same error.
I checked letter-for-letter, my code is exactly the same as the instructors and it works for him. 
What could this be? Help!
