Call to a member function get () on null

Call to a member function get() on null (View: /home/vagrant/Code/larabbs/resources/views/topics/show.blade.php)
/home/vagrant/Code/larabbs/storage/framework/views/f376c5978be7cfb7fbcc4c290a418d4bd0b41662.php#86

原因出在

@include('topics._reply_list',['replies'=>$topic->replies()->with('user')->get()]

找了一圈, 错误出在 模型关联时 没有 return !! 留此为念