Selenium error that hasn't appeared before

Code Help Python
1

Question: Why does it throw this error? Usually this code would work to my knowledge, but now it doesnt.

Repl link: https://replit.com/@kramb6920/Python-2#main.py

from selenium import webdriver
from selenium.webdriver import FirefoxOptions

opts = FirefoxOptions()
opts.add_argument("--headless")
browser = webdriver.Firefox(options=opts)

browser.get('http://example.com')

Traceback (most recent call last):
  File "main.py", line 6, in <module>
    browser = webdriver.Firefox(options=opts)
  File "/home/runner/Python-2/.pythonlibs/lib/python3.10/site-packages/selenium/webdriver/firefox/webdriver.py", line 67, in __init__
    super().__init__(command_executor=executor, options=options)
  File "/home/runner/Python-2/.pythonlibs/lib/python3.10/site-packages/selenium/webdriver/remote/webdriver.py", line 205, in __init__
    self.start_session(capabilities)
  File "/home/runner/Python-2/.pythonlibs/lib/python3.10/site-packages/selenium/webdriver/remote/webdriver.py", line 289, in start_session
    response = self.execute(Command.NEW_SESSION, caps)["value"]
  File "/home/runner/Python-2/.pythonlibs/lib/python3.10/site-packages/selenium/webdriver/remote/webdriver.py", line 344, in execute
    self.error_handler.check_response(response)
  File "/home/runner/Python-2/.pythonlibs/lib/python3.10/site-packages/selenium/webdriver/remote/errorhandler.py", line 229, in check_response
    raise exception_class(message, screen, stacktrace)
selenium.common.exceptions.WebDriverException: Message: Process unexpectedly closed with status 1
2

Try replacing this line of code:

opts.add_argument("--headless")

with this:

opts.set_headless()

The information is taken from python - selenium.webdriver.firefox.options - what is it about? - Stack Overflow