Big Sur Troubleshooting Guide

Version 2020.11.25

The Big Sur update introduces a number of major changes in macOS. One of them is disabling of the Network Kernel Extensions (NKE) API, which Proxifier for Mac v2 uses. The new Network Extensions API has been introduced to replace it. We have rewritten the network part of Proxifier to adapt to this change. Together with other improvements, Proxifier for Mac v3 has been released.

Proxifier License Upgrade

Proxifier for Mac v3 requires a new license. Upgrade options depend on the date of your v2 purchase.
If you purchased Proxifier for Mac v2 on or after:

You can extract your current v2 key using one of the following commands in Terminal:

Configuration Migration

Proxifier for Mac v3 includes the File->Import v2 Profile... menu command, which allows you to import configuration from v2. Alternatively, you can save profile to a file using File->Export... in v2 and then import the file using File->Import... in v3.

Because Proxifier for Mac v3 runs in a sandbox, it is technically impossible for it to migrate the profiles automatically.

Technical Issues

Unfortunately, the new Big Sur API is currently unstable. There are issues that persist when Proxifier is running even with an empty configuration, and they do not depend on Proxifier configuration or code. These issues have been reported to Apple, and we hope they will be resolved in future Big Sur updates.

Please feel free to contact us at support@proxifier.com. We will do our best to help you.

Special Build to Address Big Sur Problems

To mitigate the problems, we have prepared an experimental build of Proxifier for Mac v2 that supports Big Sur using private APIs.

If you have problems with Proxifier for Mac v3, you can use this build. You can also try workarounds for some known issues, which are listed below.

Applications Cannot Bind a Port for Listening
Symptoms:

Applications report errors such as "Protocol wrong type for socket", "Failed to find a free local port", and "Protocol wrong type for socket (Listen failed)".

Cause:

There is a bug in Network Extension API in the current version of macOS Big Sur. Apple has been aware of it since September. Hopefully, the problem will be fixed in the next Big Sur update.

Workarounds:
Some Applications Cannot Access the Internet
Symptoms:

Safari, built-in ssh, Cisco Webex, and other applications are unable to connect to the Internet. You have a third-party VPN or firewall product like Cisco AnyConnect or Little Snitch.

Cause:

This issue is caused by a problem in the Network Extension API. Apparently, two network extensions cannot run simultaneously in the current version of macOS Big Sur. We are working with Apple to resolve this issue.

Workarounds: