When you are testing automation in a corporate environment you may be behind an HTTP proxy. If you can run a live test successfully, but your Selenium tests fail to connect to a host, this is most likely the case. You can also recognize this by looking at the settings on your browser and how it connects to your network.
In this situation any automated programs you run from your machine must be aware and use the HTTP proxy or your programs may not work.
The error will show up as an unable to connect to remote host and when you run an automated test it will not show up in your testing dashboard. You could also see errors from the Remote browser object you used to connect to the hub at CrossBrowserTesting.com. The test will die quickly in most cases.
To fix this you must tell the programming language you are using about the proxy.
For Java you can find information on setting the HTTP proxy here: http://docs.oracle.com/javase/7/docs/technotes/guides/net/proxies.html
For python see this article http://stackoverflow.com/questions/11726881/how-to-set-an-http-proxy-in-…
For CSharp see this article http://stackoverflow.com/questions/1938990/c-sharp-connecting-through-proxy