Note: Starting with this build, Insiders in the Dev Channel have the option to receive builds from the RS_PRERELEASE branch. They will be offered as an optional update for “seekers” who manually go to Settings > Update & Security > Windows Update and check for new builds. Starting today seekers can install build 21277. Here is what Microsoft says regarding the announcement:

Windows 10 Build 20277

Here is the list of fixes contained in today’s release: Insiders who choose to stay put will continue to automatically get builds from the FE_RELEASE until we move all Insiders in the Dev Channel to receiving RS_PRERELEASE builds sometime after the holidays.

We fixed an issue that could result in the WinRE volume label being lost after multiple upgrades.We fixed an issue that could result in apps failing to update with error code 0x80073D02.

Keep in mind that Insider builds are meant for coders, IT admins, and Windows 10 enthusiasts who want to test new features and submit feedback to Microsoft. These builds are not meant for inexperienced users. They are also not meant to run on your primary production machine. Insider builds contain many known stability issues that can cause your system to become unstable or even crash. For more on this build’s full list of changes, known issues, and workarounds make sure to read Microsoft’s full blog post.

Microsoft Releases Windows 10 Build 20277 - 75Microsoft Releases Windows 10 Build 20277 - 48Microsoft Releases Windows 10 Build 20277 - 22