启动RN的时候刚开始报错：
The request was denied by service delegate (SBMainWorkspace) for reason: Security ("Entitlement "com.apple.frontboard.debugapplications" required to launch applications for debugging").
查询网络上的解决办法是：
删掉/Users/用户名/资源库/Developer/CoreSimulator/Devices里面的东西，都删除以后在启动有报错如下：
xcode Unable to boot device because it cannot be located on disk
解决办法是：
打开模拟器：Hardware > Device > Manage Devices
把没用的模拟器全部删除，然后在添加回来，
最后一定要重启模拟器，再重新启动项目即可以。