[🐛 Bug]: Chrome 142 blocking local extensions

[mattsmith321]

Description

Looks like Chrome 142 is now restricting access to the local network. See the following:

• https://support.netdocuments.com/s/article/ndClick-Not-Running-With-Chrome-142
• https://www.ghacks.net/2025/10/29/google-chrome-142-restricts-local-network-access-and-changes-sync-on-desktop/
• https://cr-status.appspot.com/feature/5152728072060928?gate=5142408070955008
• https://github.com/WICG/local-network-access/blob/main/explainer.md

This is causing our automated testing solution built on .NET + NUnit + Selenium +Selenium Grid to fail tests that run on Chrome 142. I just saw it pop up this weekend. I'm hoping there are some flags I can add to the code to deal with it. Tried updating to Selenium.WebDriver and Selenium.Support 4.38 (from 4.35) but the issue still persists.

I saw some references to adding a list of IPs to allow but it gets a little tricky with our framework since people can run it from different machines across the network.

Also note that it doesn't throw an error when trying to load the extension via code. It just displays a broken page and the script fails since the fields it needs to interact with do not exist. The Chrome page presented says:

dfkasdlkfladfld is blocked
This page has been blocked by Chrome
ERR_BLOCKED_BY_CLIENT

Reproducible Code

ChromeOptions options = new ChromeOptions();

// Chrome v137 disabled loading unpacked extensions. This argument overrides that.
// See https://github.com/SeleniumHQ/selenium/issues/15788
options.AddArgument("--disable-features=DisableLoadExtensionCommandLineSwitch");

// Add the MultiPass extension to avoid the Windows Basic Authentication prompts
options.AddExtensions(TestContext.CurrentContext.TestDirectory + _config.MultiPassExtensionPath);

---

ℹ️ Last known working version: Worked fine until Chrome 142

[selenium-ci]

@mattsmith321, thank you for creating this issue. We will troubleshoot it as soon as we can.

Selenium Triage Team: remember to follow the Triage Guide

[mattsmith321]

I'm going to close this issue as I see that the 137 workaround no longer works. For now I am target CfT by forcing download of a specific version. It works locally. Trying to get it to work on Selenium Grid now.

                ChromeOptions options = new ChromeOptions();

                // Target a specific Chrome for Testing version
                options.BrowserVersion = "142.0.7444.59";

                // Force Selenium Manager to download/use that browser binary,
                // not the locally-installed Chrome.
                options.AddAdditionalOption("se:forceBrowserDownload", true);

I know that I need to switch to DevTools Network auth handler / NetworkInterceptor to inject Authorization: Basic to deal with the basic auth prompt but I tried that earlier this year and the performance was terrible. I will revisit.