我用mac 和朋友的mac 试了创建helloword 和 体验demo 都无法运行，提示渲染失败。下面是异常，好几个版本都都没解决，用win开发太不方便了还要切系统，是mac要配置什么吗？

Mon Dec 18 2017 00:10:57 GMT+0800 (CST) 渲染层错误

VM104:2 WebSocket connection to ‘ws://127.0.0.1:9974/’ failed: Error in connection establishment: net::ERR_CONNECTION_TIMED_OUT

(anonymous) @ VM104:2

3appservice:1088 WebSocket connection to ‘ws://127.0.0.1:9974/’ failed: Error in connection establishment: net::ERR_CONNECTION_TIMED_OUT