SeleniumHQ/selenium · error · Selenium::WebDriver::Error::WebDriverError

Could not find a valid devtools version; use a more recent v

Error message

Could not find a valid devtools version; use a more recent version of selenium-devtools gem

What it means

Raised by Selenium::Devtools.load_older_version (devtools.rb) after both v-1 and v-2 fallback requires fail with LoadError. It means the installed selenium-devtools gem has no protocol module matching the browser's CDP version within two major versions. The fix is to install a newer selenium-devtools gem.

Source

Thrown at rb/lib/selenium/devtools.rb:42

      def load_version
        require "selenium/devtools/v#{@version}"
      rescue LoadError
        WebDriver.logger.warn "Could not load selenium-devtools v#{@version}. Trying older versions.",
                              id: :devtools
        load_older_version
      end

      private

      # Try to load up to 2 versions back
      def load_older_version
        load_old_version(@version - 1)
      rescue LoadError
        begin
          load_old_version(@version - 2)
        rescue LoadError
          raise WebDriver::Error::WebDriverError,
                'Could not find a valid devtools version; use a more recent version of selenium-devtools gem'
        end
      end

      def load_old_version(version)
        require "selenium/devtools/v#{version}"
        self.version = version
        msg = "Using selenium-devtools version v#{version}, some features may not work as expected."
        WebDriver.logger.warn msg, id: :devtools
      end
    end
  end # DevTools
end # Selenium

View on GitHub (pinned to aa36b38e69)

Solutions

Update the selenium-devtools gem: gem install selenium-devtools or bundle update selenium-devtools.
Keep selenium-webdriver and selenium-devtools on the same release line.
Downgrade the browser to one whose CDP version the gem supports, if upgrading the gem is not possible.

Example fix

# before
# Gemfile.lock pins selenium-devtools 0.114.0 with Chrome 131
# after
gem 'selenium-devtools', '~> 0.131'
# then: bundle update selenium-devtools

Defensive patterns

Strategy: fallback

Validate before calling

require 'rubygems'
begin
  gem 'selenium-devtools', '>= ' + @version.to_s
rescue Gem::MissingSpecVersionError
  warn 'selenium-devtools too old for CDP v' + @version.to_s + '; upgrade the gem'
end

Try / catch

begin
  Selenium::DevTools.load_version
rescue Selenium::WebDriver::Error::WebDriverError => e
  raise unless e.message.include?('valid devtools version')
  system('gem install selenium-devtools') or
    raise 'Install a newer selenium-devtools gem to match your browser CDP version'
end

Prevention

Keep selenium-devtools and selenium-webdriver on the same release line.
Run bundle update selenium-devtools when upgrading the browser.
Pin the browser to a CDP version the installed gem supports if you cannot upgrade.

When it happens

Trigger: load_version fails to require selenium/devtools/v{@version}; load_older_version tries v-1, then v-2, both raise LoadError, so it raises WebDriver::Error::WebDriverError (devtools.rb:36-45).

Common situations: A very new Chrome/Edge whose CDP version is more than 2 ahead of the installed gem; an outdated selenium-devtools gem pinned in a Gemfile/lockfile; major version drift between selenium-webdriver and selenium-devtools.

Related errors

AI-assisted analysis of SeleniumHQ/selenium@aa36b38e69 (2026-08-14). Data as JSON: /api/errors/b96a58d390a617d4. Report an issue: GitHub.