Apple Seeds MacOS Sierra 10.12.3 Beta 4 to Developers
01/13/2017
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Apple has seeded macOS Sierra 10.12.3 beta 4 to developers for testing. The build number is 16D30a.
The macOS Sierra 10.12.3 update improves the stability, compatibility, and security of your Mac.

You can install this update using the MacOS Sierra Developer Beta:
After running the installer, the Mac App Store will open automatically. Click the Updates panel and the latest version of macOS developer beta will be available for download.
Source: iclaried