[Python] Selenium SessionNotCreatedException: "User data directory is already in use" when...

I am trying to launch a headless Chrome WebDriver using Selenium in Python. However, I keep encountering this error:

selenium.common.exceptions.SessionNotCreatedException: Message: session not created: probably user data directory is already in use,
please specify a unique value for --user-data-dir argument, or don't use --user-data-dir


Here is my current implementation:

from selenium import webdriver
from selenium.webdriver.chrome.service import Service
from webdriver_manager.chrome import ChromeDriverManager

def createModel():
service = Service(ChromeDriverManager().install())
options = webdriver.ChromeOptions()

# Specifying user data directory
options.add_argument("--user-data-dir=/tmp/selenium-user-data")
options.add_argument("--headless=new")
options.add_argument("--start-maximized")

driver = webdriver.Chrome(service=service, options=options)
return driver

driver = createModel()
driver.get("https://www.google.com")
print(driver.title)
driver.quit()

What I Have Tried:

1. Removing --user-data-dir → Still getting the error.
2. Using a unique temp directory for --user-data-dir:
   import tempfile
   options.add_argument(f"--user-data-dir={tempfile.mkdtemp()}")
   
   Still, the error persists.
3. Killing existing Chrome processes using pkill -9 chrome before running Selenium → No effect.
4. Running Chrome without headless mode → The error persists.

Additional Information:

• OS: Ubuntu 22.04
• Chrome Version: (latest stable version)
• Selenium Version: (latest)
• Chromedriver Version: (latest via webdriver_manager)
• Running inside a Docker container? No

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