fail to excute node server.js

[Chambers1994]

I hava try twice, but it didn't work, I config my /etc/turnserver.conf based this github guidance, but then:
air@air-G3-3590:~/webRTC/webrtc_server$ node server.js
/home/air/webRTC/webrtc_server/node_modules/express/lib/router/index.js:458
throw new TypeError('Router.use() requires a middleware function but got a ' + gettype(fn))
^

TypeError: Router.use() requires a middleware function but got a Null
at Function.use (/home/air/webRTC/webrtc_server/node_modules/express/lib/router/index.js:458:13)
at Function. (/home/air/webRTC/webrtc_server/node_modules/express/lib/application.js:220:21)
at Array.forEach ()
at Function.use (/home/air/webRTC/webrtc_server/node_modules/express/lib/application.js:217:7)
at Object. (/home/air/webRTC/webrtc_server/server.js:9:5)
at Module._compile (internal/modules/cjs/loader.js:1147:30)
at Object.Module._extensions..js (internal/modules/cjs/loader.js:1167:10)
at Module.load (internal/modules/cjs/loader.js:996:32)
at Function.Module._load (internal/modules/cjs/loader.js:896:14)
at Function.executeUserEntryPoint [as runMain] (internal/modules/run_main.js:71:12)
air@air-G3-3590:~/webRTC/webrtc_server$ node server.js

Your help will be appreciated!

[ZhuoSir]

解决了吗