Cannot Start The Driver Service - On Http Localhost Selenium Firefox C [best]

For Java:

If your machine relies on a proxy or a VPN, Selenium might attempt to route its internal loopback ( localhost ) traffic through that external proxy. You can correct this behavior via environment configurations or directly in your C# code. Option A: Direct C# Code Fix

Incompatibility between Firefox, GeckoDriver, and Selenium versions. For Java: If your machine relies on a

If you are encountering this error, follow these steps in order. They are designed to systematically eliminate the most common and likely causes.

Ensure that your local antivirus or Windows Defender is not quarantining geckodriver.exe or blocking local network loopback connections. 4. Address Mismatched Architecture and Permissions If you are encountering this error, follow these

In the vast majority of cases, the problem is resolved by one of these three actions:

This approach ensures you always have the correct driver version without manual intervention. If you are encountering this error

In some environments, a proxy server might interfere with Selenium's attempt to communicate with the driver on Stack Overflow environment variable with the value to bypass proxy settings for local traffic. Stack Overflow 4. Verify Architecture and Version Compatibility