未定义的属性：Illuminate \ Http \ RedirectResponse :: $ admin_id

Question

如果用户访问不存在的帖子的管理页面（如“ https://proj.test/post/manage/34”），为什么会出现： Undefined property: Illuminate\Http\RedirectResponse::$admin_id？

错误在于AuthServiceProvider的引导方法中：

 public function boot(GateContract $gate)
    {
        $this->registerPolicies();
        $gate->define('access-management-area', function($user, $post)
        {
            return $user->id == $post->admin_id;
        });
    }