Invalid session ID
The invalid session ID error is a WebDriver error that occurs when the server does not recognize the unique session identifier. This happens if the session has been deleted or if the session ID is invalid.
Example
Explicit session deletion
A WebDriver session is explicitly deleted when quitting:
python
from selenium import webdriver
from selenium.common import exceptions
session = webdriver.Firefox()
print("Current session is {}".format(session.session_id))
session.quit()
try:
session.get("https://mozilla.org")
except exceptions.InvalidSessionIdException as e:
print(e.message)
Output:
Current session is 46197c16-8373-469b-bc56-4c4d9e4132b4 No active session with ID 46197c16-8373-469b-bc56-4c4d9e4132b4
Implicit session deletion
The session can also be implicitly deleted if you close the last window or tab:
python
from selenium import webdriver
from selenium.common import exceptions
session = webdriver.Firefox()
print("Current session is {}".format(session.session_id))
# closes current window/tab
session.close()
try:
session.get("https://mozilla.org")
except exceptions.InvalidSessionIdException as e:
print(e.message)
Output:
Current session is 46197c16-8373-469b-bc56-4c4d9e4132b4 No active session with ID 46197c16-8373-469b-bc56-4c4d9e4132b4
See also
- List of WebDriver errors
- Session not created
- Related WebDriver commands: