Xcode 模拟器运行提示xcode Unable to boot device because it cannot be located on disk

打开Xcode -> Open Developer Tool -> iOS simulator

在打开的模拟器上选择

Hardware -> Device -> Manage Devices

把没用的模拟器全部删除，然后再添加回来就可以了。添加是立刻的，不需要下载。