Known Issue: pac code run throwing System.Net.HttpListenerException on Windows

[jordanchodakWork]

We’ve identified that this error may occur due to a recent Windows Defender update that temporarily blocked the creation of local host servers for certain applications, including PAC-CLI.

For details on the issue, refer to: KB5066835 Breaks Local IIS on Windows 11: Mitigations and Rollback Guide | Windows Forum

The good news: Windows Defender has released an update that resolves this problem. If you’re still encountering the error, please follow these steps:

1. Update Windows Defender: Ensure your Windows Defender is running the latest security intelligence updates. You can verify the current version here: Latest security intelligence updates for Microsoft Defender Antivirus and other Microsoft antimalware - Microsoft Security Intelligence

2. Restart your computer: After updating, restart your device to apply the changes.