I am trying to get Protractor up and running following the official Getting Started Guide.
The command
webdriver-manager start
seem
I had a similar problem in my environment (Mac OS X 10.8.5).
After struggling it for more than an hour, I finally installed the older version (1.4.0) of the protractor and it works very fine.
npm install -g protractor@1.4.0
If you would use grunt task grunt-protractor-webdriver, you should use the version 0.1.9 which is working properly in my env. Its 0.2.0 version doesn't work for me. thanks.