SeleniumHQ/selenium · error · OSError

Can't find server .jar located at {path}

Error message

Can't find server .jar located at {path}

What it means

Raised as OSError by the Server.path setter when a path is provided but os.path.exists returns False. The setter validates existence immediately on assignment so the user discovers a wrong path at configuration time rather than at server start time.

Source

Thrown at py/selenium/webdriver/remote/server.py:100

        return self._startup_timeout

    @startup_timeout.setter
    def startup_timeout(self, timeout):
        self._startup_timeout = int(timeout)

    @property
    def status_url(self):
        host = self.host if self.host is not None else "localhost"
        return f"http://{host}:{self.port}/status"

    @property
    def path(self):
        return self._path

    @path.setter
    def path(self, path):
        if path and not os.path.exists(path):
            raise OSError(f"Can't find server .jar located at {path}")
        self._path = path

    @property
    def port(self):
        return self._port

    @port.setter
    def port(self, port):
        try:
            port = int(port)
        except ValueError:
            raise TypeError(f"{__class__.__name__}.__init__() got an invalid port: '{port}'")
        if not (0 <= port <= 65535):
            raise ValueError("port must be 0-65535")
        self._port = port

    @property
    def version(self):

View on GitHub (pinned to aa36b38e69)

Solutions

1. Verify the path exists before passing it: os.path.exists(path)
2. Use an absolute path with os.path.abspath or pathlib.Path.resolve()
3. Download the Selenium Grid jar first if it is not yet present

Example fix

// before
server = Server(path='selenium-server.jar')  # relative, wrong CWD

// after
import os
jar = os.path.abspath('/opt/selenium/selenium-server.jar')
server = Server(path=jar)

import os
jar_path = '/opt/selenium-server.jar'
if not os.path.exists(jar_path):
    raise FileNotFoundError(f'Server jar not found: {jar_path}')
server = Server(path=jar_path)

import os
def jar_exists(path: str) -> bool:
    return bool(path) and os.path.exists(path)

try:
    server = Server(path=jar_path)
except OSError:
    download_selenium_jar(jar_path)  # fetch then retry
    server = Server(path=jar_path)

When it happens

Trigger: Calling Server(path='/nonexistent/selenium-server.jar') or server.path = '/wrong/path.jar' triggers the OSError. The path must point to an existing file before assignment.

Common situations: Typo in the jar path. Wrong working directory for relative paths. CI environments where the jar hasn't been downloaded yet. Paths from config that reference a location not present on the current machine.

Related errors

• Add-on path does not exist: {addon_path}
• Not allowed to specify a version when using an existing serv
• {__class__.__name__}.__init__() got an invalid port: '{port}
• port must be 0-65535
• {__class__.__name__}.__init__() got an invalid version: '{ve

AI-assisted analysis of SeleniumHQ/selenium@aa36b38e69 (2026-08-14). Data as JSON: /api/errors/6ffdac6d6ab7d9e5. Report an issue: GitHub.