HOW TO GET IT:
• If your console is in Instant-On mode and you have been selected to receive the update, it will download and install the update and reboot to standby.
• NOTE: Once the update is available to you, you can manually begin the update by launching the Guide and navigating to All Settings > System > Updates.
• If your console hasn’t downloaded and installed the update by 1:00 AM PST 11/11/2017 (9:00AM GMT 11/11), you will be prompted to do so at that time.
• NOTE: This update has a shorter than usual amount of time before it becomes mandatory.
OS version released: rs3_release_xbox_dev_1711.171107-1922
Available: 2:00PM PST 11/10 (10:00PM GMT 10/11)
• Party Chat
• Additional fixes to address issues which sometimes cause stuttering or popping in party chat audio.
• Fixed an issue which sometimes caused party chat to unexpectedly crash.
• Games & Apps
• Fixed an issue which sometimes prevented games from launching.
• Miscellaneous performance improvements.
• Game DVR
Resolved an issue which could prevent Game DVR from recording audio in game clips.
Fixed an issue which caused downscaled video to play when viewing 4K video trailers in the Store.
Fixed issues which could prevent players from matchmaking or joining matches.
Fixed an issue which sometimes prevented Dolby Atmos audio from outputting correctly.
Resolved issues with Narrator stopping before it finishes reading text.
• The left and right navigation for selecting date and time during Tournament creation is currently reversed when the console language is set to Arabic or Hebrew.
• Left and right navigation in Tournament twists is reversed when the console language is set to Arabic or Hebrew.
• Left and right navigation in the bracket view of Tournaments is reversed when the console language is set to Arabic or Hebrew.
• Avatars on Home
Users wishing to represent themselves as an avatar can do so by changing their settings under My profile > Customize profile > Show my avatar.
• Activity Feed
Game clips from the activity feed may appear blank.
Quelle: Xbox Insider Forum