[🐛 Bug]: Unknown Error，the error message is empty

[melon-bun]

What happened?

When using Selenium to launch Chrome, the browser does not open, and instead, an error occurs. However, the error message is blank.

How can we reproduce the issue?

selenium version：4.27.1
from selenium.webdriver.chrome.service import Service
from selenium import webdriver
from webdriver_manager.chrome import ChromeDriverManager
chromedriver_path = "M:/chromedriver-win64/chromedriver-win64/chromedriver.exe" 

service = Service(executable_path=chromedriver_path)
options = webdriver.ChromeOptions()
options.add_argument("--disable-extensions")
driver = webdriver.Chrome(service=service, options=options)
try:
    driver.get("https://www.google.com")
except Exception as e:
    print(f"error: {e}")

Relevant log output

WebDriverException                        Traceback (most recent call last)
Cell In[1], line 15
     13 options = webdriver.ChromeOptions()
     14 options.add_argument("--disable-extensions")
---> 15 driver = webdriver.Chrome(service=service, options=options)
     17 try:
     19     driver.get("https://www.google.com")

File d:\program files\python38\lib\site-packages\selenium\webdriver\chrome\webdriver.py:69, in WebDriver.__init__(self, executable_path, port, options, service_args, desired_capabilities, service_log_path, chrome_options, service, keep_alive)
     66 if not service:
     67     service = Service(executable_path, port, service_args, service_log_path)
---> 69 super(WebDriver, self).__init__(DesiredCapabilities.CHROME['browserName'], "goog",
     70                                 port, options,
     71                                 service_args, desired_capabilities,
     72                                 service_log_path, service, keep_alive)

File d:\program files\python38\lib\site-packages\selenium\webdriver\chromium\webdriver.py:93, in ChromiumDriver.__init__(self, browser_name, vendor_prefix, port, options, service_args, desired_capabilities, service_log_path, service, keep_alive)
     90 self.service.start()
     92 try:
---> 93     RemoteWebDriver.__init__(
     94         self,
     95         command_executor=ChromiumRemoteConnection(
     96             remote_server_addr=self.service.service_url,
     97             browser_name=browser_name, vendor_prefix=vendor_prefix,
     98             keep_alive=keep_alive, ignore_proxy=_ignore_proxy),
     99         options=options)
    100 except Exception:
    101     self.quit()

File d:\program files\python38\lib\site-packages\selenium\webdriver\remote\webdriver.py:266, in WebDriver.__init__(self, command_executor, desired_capabilities, browser_profile, proxy, keep_alive, file_detector, options)
    264 self.file_detector = file_detector or LocalFileDetector()
    265 self.start_client()
--> 266 self.start_session(capabilities, browser_profile)

File d:\program files\python38\lib\site-packages\selenium\webdriver\remote\webdriver.py:357, in WebDriver.start_session(self, capabilities, browser_profile)
    354 w3c_caps = _make_w3c_caps(capabilities)
    355 parameters = {"capabilities": w3c_caps,
    356               "desiredCapabilities": capabilities}
--> 357 response = self.execute(Command.NEW_SESSION, parameters)
    358 if 'sessionId' not in response:
    359     response = response['value']

File d:\program files\python38\lib\site-packages\selenium\webdriver\remote\webdriver.py:418, in WebDriver.execute(self, driver_command, params)
    416 response = self.command_executor.execute(driver_command, params)
    417 if response:
--> 418     self.error_handler.check_response(response)
    419     response['value'] = self._unwrap_value(
    420         response.get('value', None))
    421     return response

File d:\program files\python38\lib\site-packages\selenium\webdriver\remote\errorhandler.py:207, in ErrorHandler.check_response(self, response)
    205     value = response['value']
    206 if isinstance(value, str):
--> 207     raise exception_class(value)
    208 if message == "" and 'message' in value:
    209     message = value['message']

WebDriverException: Message:

Operating System

Window 11

Selenium version

4.27.1 python

What are the browser(s) and version(s) where you see this issue?

Chrome 133.0.6943.127

What are the browser driver(s) and version(s) where you see this issue?

Chromedriver 133.0.6943.127

Are you using Selenium Grid?

No response

[github-actions]

@melon-bun, thank you for creating this issue. We will troubleshoot it as soon as we can.

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Thank you!

[cgoldberg]

@melon-bun

Can you upgrade to the latest version of selenium (4.29) and verify this is reproducible? We only support the latest version.

Unfortunately, it looks like you are using Python 3.8... which is no longer supported with the latest selenium package. You might need to upgrade your version of Python as well if 3.8 gives you issues.

[Lqlsoftware]

Same issue with latest version of selenium (4.29) after my Chrome automatically updated.
It seems not compatible with the newest version of Chrome (133.0.6943.142).

[Lqlsoftware]

Update for temporary solution:
Manually start a chromedriver demon before starting any selenium session.
Just run chromedriver in another terminal window.

[cgoldberg]

@Lqlsoftware
Are you also on Windows?

chrome/chromedriver 133 works fine for me on Linux, running the code from the original post in this thread.

[Lqlsoftware]

@cgoldberg
Sorry, I'm on MacOS 15.3.1.
After executing chromedriver and kill it, everything works fine for me now.
Maybe there was some problems that preventing seleinum from starting up chromedriver?