Apple has released the sixth beta of an upcoming macOS Sierra 10.12.2 update to developers and public beta testers. Developers can download the beta through the Apple Developer Center or the Software Update mechanism in the App Store.
If you’re not already signed up for the public beta program, you can do sign up at .https://beta.apple.com/sp/betaprogram/ . The public beta program is free, but remember: beta software is unfinished software so use with care.