iOS在后台shutdown操作程序崩溃

我现在在收到内存警告的时候打算把不再显示页面的视频播放器全部释放掉，我的代码是：
[self.player shutdown];
[self.playerBaseView removeFromSuperview];
self.playerBaseView = nil;
当收到内存警告的时候，didReceiveMemoryWarning 方法把每一个界面的视频播放器释放掉之后崩溃掉了。。。。请问应该怎么处理？如果有更好的解决方案也可以告诉我。

No file or test is named. Start at the iOS didReceiveMemoryWarning path and the [self.player shutdown] call shown in the report, then reproduce the crash while releasing off-screen players. Done means the shutdown and view-removal sequence no longer crashes during a memory warning.

Written by the indexing model from the issue text.