title: InvalidArgumentException: Message: invalid argument: user data directory is already in use error using --user-data-dir to start Chrome using Selenium
body: <p>When I am trying to use <code>--user-data-dir</code> for the current user to start Chrome using Selenium I am getting an error as:</p>
  
  <pre><code>  File "C:\Program Files (x86)\Python\lib\site-packages\selenium\webdriver\remote\webdriver.py", line 321, in execute
      self.error_handler.check_response(response)
    File "C:\Program Files (x86)\Python\lib\site-packages\selenium\webdriver\remote\errorhandler.py", line 242, in check_response
      raise exception_class(message, screen, stacktrace)
  selenium.common.exceptions.InvalidArgumentException: Message: invalid argument: user data directory is already in use, please specify a unique value for --user-data-dir argument, or don't use --user-data-dir
  </code></pre>
  
  <p>How can I fix this error?</p>