Here is how you resolve the error, ranked from most likely to least likely:
service = Service(port=7056) # default is 7055
When you run a Selenium script for Firefox, Selenium tries to start geckodriver (the bridge between your code and Firefox). geckodriver runs an HTTP server on http://localhost:someport . If that server fails to start — Selenium throws the error you see. Here is how you resolve the error, ranked
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The most frequent cause is a firewall or VPN blocking the communication between your script and the Stack Overflow Temporarily disable your Let me know if you want to add anything else
If you absolutely need a specific port (e.g., for CI/CD or debugging), you can set it:
from selenium import webdriver
The error is a common headache for C# developers using Selenium with Firefox. It typically means the GeckoDriver executable is unable to establish a local network connection to start its internal server. 🛠️ Root Causes Port Conflicts: Another process is using the default port. Loopback Issues: localhost isn't resolving to 127.0.0.1 .