Unreal Header Tool fails for target - solution wont build for 'TwinShooterProjectEditor'

GENERATED_BODY() sets all members private, but UPROPERTY with BlueprintReadWrite or BluePrintReadOnly need to be public.

Try to change it like this:

GENERATED_BODY()

public:
         UPROPERTY(BlueprintReadWrite, EditAnywhere, Category = "Hero")
             float Health = 100;

         UPROPERTY(BlueprintReadOnly, VisibleAnywhere, Category = "Hero")
             bool isDead = false;

private:
...