The error "OpenQA.Selenium.WebDriverException: Cannot start the driver service on http://localhost:PORT/" in Selenium for C# usually occurs when the GeckoDriver (Firefox's driver) executable cannot be located, is blocked by system settings, or is incompatible with the installed browser version. Core Reasons for This Error
Compatibility issues between the browser and driver are a frequent cause of startup failures. Stack Overflow Version Match: Ensure your geckodriver version supports your current Firefox version. Architecture: Check if you are running a binary on a
Manually run GeckoDriver
In terminal: geckodriver
It should say Listening on http://0.0.0.0:4444 (or random port). If it crashes immediately, you have a version mismatch or corrupted binary.
If you're automating Firefox using Selenium WebDriver, you've likely encountered this frustrating error:
Firefox not installed or not found in default location.
Fix:
Ensure the FirefoxDriverService is pointing to the directory containing geckodriver.exe, not the executable file itself.
The error "OpenQA.Selenium.WebDriverException: Cannot start the driver service on http://localhost:PORT/" in Selenium for C# usually occurs when the GeckoDriver (Firefox's driver) executable cannot be located, is blocked by system settings, or is incompatible with the installed browser version. Core Reasons for This Error
Compatibility issues between the browser and driver are a frequent cause of startup failures. Stack Overflow Version Match: Ensure your geckodriver version supports your current Firefox version. Architecture: Check if you are running a binary on a The error "OpenQA
Manually run GeckoDriver
In terminal: geckodriver
It should say Listening on http://0.0.0.0:4444 (or random port). If it crashes immediately, you have a version mismatch or corrupted binary. Update the test configuration to use the correct
If you're automating Firefox using Selenium WebDriver, you've likely encountered this frustrating error: Ensure the FirefoxDriverService is pointing to the directory
Firefox not installed or not found in default location.
Fix:
Ensure the FirefoxDriverService is pointing to the directory containing geckodriver.exe, not the executable file itself.