If you’re getting this error
Selenium::WebDriver::Error::WebDriverError, it’s probably because you have the chromedriver-helper gem installed.
gem 'rails', '~> 5.2.4', '>= 126.96.36.199' and
ruby 2.5.0p0 (2017-12-25 revision 61468)
Simply by switching out the webdrivers gem for the chromedriver-helper gem, my error message was gone and I could go back to testing.
I ran into this because I hadn’t started a new rails project in some time and the updated changes bit me.
Hope this helps!