SeleniumHQ/selenium · error · Error::WebDriverError

could not find extension at #{path.inspect}

Error message

could not find extension at #{path.inspect}

What it means

The deprecated Chromium::Profile#add_extension (Chrome::Profile / Edge::Profile) raises Error::WebDriverError when no regular file exists at the given path. Profile-based extension loading is deprecated in favor of Options#add_extension; the same file-existence check applies.

Source

Thrown at rb/lib/selenium/webdriver/chromium/profile.rb:44

      class Profile
        include ProfileHelper

        def initialize(model = nil)
          WebDriver.logger.deprecate(
            'Chromium::Profile (including Chrome::Profile and Edge::Profile)',
            "Options#add_argument('--user-data-dir=...'), Options#add_preference, and Options#add_extension",
            id: :chromium_profile
          )

          @model = verify_model(model)
          @extensions = []
          @encoded_extensions = []
          @directory = nil
        end

        def add_extension(path)
          raise Error::WebDriverError, "could not find extension at #{path.inspect}" unless File.file?(path)

          @extensions << path
        end

        def add_encoded_extension(encoded)
          @encoded_extensions << encoded
        end

        def directory
          @directory || layout_on_disk
        end

        #
        # Set a preference in the profile.
        #
        # See https://src.chromium.org/viewvc/chrome/trunk/src/chrome/common/pref_names.cc
        #

View on GitHub (pinned to aa36b38e69)

Solutions

1. Migrate to Options#add_extension (the supported API): options.add_extension(path).
2. Pass an absolute path to an existing .crx file.
3. Verify the file exists with File.file?(path) before calling.
4. Heed the :chromium_profile deprecation warning and switch to Options-based config.

Example fix

// before
profile = Selenium::WebDriver::Chrome::Profile.new
profile.add_extension('ext.crx')
// after
options = Selenium::WebDriver::Chrome::Options.new
options.add_extension(File.expand_path('ext.crx', __dir__))

raise 'migrate to Options' if defined?(profile)
# Use the supported API:
options.add_extension(path) if File.file?(path) && File.extname(path) == '.crx'

def valid_extension_path?(path)
  File.file?(path) && File.extname(path).casecmp?('.crx')
end

begin
  profile.add_extension(path)
rescue Selenium::WebDriver::Error::WebDriverError => e
  raise unless e.message =~ /could not find extension/
  options.add_extension(File.expand_path(path, __dir__))
end

When it happens

Trigger: Calling profile.add_extension(path) on a Chromium::Profile/Chrome::Profile/Edge::Profile where File.file?(path) is false.

Common situations: Using the old Profile API instead of Options, relative path issues, missing .crx at runtime, following outdated examples.

Related errors

• could not find extension at #{path.inspect}
• Path to the extension doesn't exist
• #{model}
• argument can not be null
• Port needs to be an integer

AI-assisted analysis of SeleniumHQ/selenium@aa36b38e69 (2026-08-14). Data as JSON: /api/errors/ff5372fea7fce289. Report an issue: GitHub.