Fixing 'No response from server for url http://localhost:7055/hub/session/' problems with Selenium

If you’re using a Windows Server 2008 R2 for your CI builds and tests, you may run into issues with running Selenium tests that Server 2003 didn’t have. It took me a good 1/2 day of trial and error to fix the problem, but it’s so obscure I thought I’d share. The error you’ll see from Selenium is usually this one:

“No response from server for url http://localhost:7055/hub/session/…”

The error is actually FirefoxDriver related rather than Selenium itself, although ChromeDriver may just fail silently. The problem comes from the security of the default Temp directory on Windows 2008/2007. The solution is fairly straight forward, change the global environmental TEMP and TMP variables to a directory that has read/write access by the Everyone user - for example C:\temp. You can do this via

Computer->Properties->Advanced System Settings->Environment Variables->System Variables.

It’s a small security risk but as it’s only a build box it shouldn’t matter much, and fixes the issue.

I found the clue to the solution from this newsgroup posting

I'm Chris Small, a software engineer working in London. This is my tech blog. Find out more about me via Github, Stackoverflow, Resume