Port 8081 already in use
cd /Library/LaunchDaemons
sudo launchctl unload com.mcafee.agent.macmn.plist
No bundle URL present
react-native start //如果不行 尝试下方方法
sudo launchctl remove com.mcafee.agent.macmn
npm install //如果失败,可以尝试npm init先
cd /Library/LaunchDaemons
sudo launchctl unload com.mcafee.agent.macmn.plist
react-native start //如果不行 尝试下方方法
sudo launchctl remove com.mcafee.agent.macmn
npm install //如果失败,可以尝试npm init先