In my experience, using Selenium-Webdriver 2.45.0 and Firefox v 35.0 will work. If you have a newer version of Firefox installed, you must uninstall it first. If you are running MacOS, you may have to turn off automatic updates in Firefox before you can roll back to v 35.0 (they are enabled by default and start immediately when Firefox opens ...).
The version of Capybara / Cucumber should not matter if everything else is set correctly (this is just loading the driver anyway).
https://ftp.mozilla.org/pub/mozilla.org/firefox/releases/
Btw, never use “package update” or “gem update” arbitrarily. It's like saying "give me the latest versions of all gems from all available sources" without knowing the effects before. This may be a Pandora Box problem if you are not careful, especially the “package update”.
etusm source share