When trying to update OpenSSL - I broke (seemingly) everything surrounding Ruby and Rails on my laptop. Even after uninstalling ruby and rails through gem uninstall
I was able to resolve this problem by simply running gem install rails.
This problem occurred when I cloned a pre-existing Rails 4 app. I am using ruby-2.0.0-p317, and an RVM gemset specific to this app. I ran the initial bundle install, but then could not run rails console without getting the error.
After running gem install rails, which used the cached copy in my app's gemset, the problem was resolved. Don't ask my why!