cortex-test doesn't work with newly-created project

[kaelzhang]

Air:b Kael$ cortex test
info: Testing test/b.js
info: open browser to visit http://127.0.0.1:1976/b.html
/usr/local/lib/node_modules/cortex-test/node_modules/express/node_modules/etag/index.js:55
    throw new TypeError('argument entity must be string, Buffer, or fs.Stats')
          ^
TypeError: argument entity must be string, Buffer, or fs.Stats
    at etag (/usr/local/lib/node_modules/cortex-test/node_modules/express/node_modules/etag/index.js:55:11)
    at SendStream.setHeader (/usr/local/lib/node_modules/cortex-test/node_modules/express/node_modules/send/index.js:724:15)
    at SendStream.send (/usr/local/lib/node_modules/cortex-test/node_modules/express/node_modules/send/index.js:500:8)
    at onstat (/usr/local/lib/node_modules/cortex-test/node_modules/express/node_modules/send/index.js:585:10)
    at Object.oncomplete (fs.js:97:15)
ERR! Not ok, exit code: 1