The latest content update for Halo: The Master Chief Collection includes Halo 4’s Spartan Ops and continued fixes to matchmaking, custom games, and UI improvements.  The whooping 3GB update will be available next time you launch the game.  Some key fixes in this update along with the release of Spartan Ops includes not allowing matchmaking games not start unless there are even teams and resolving issues where a player would get stuck “Joining Session”.  Here’s the list which can also be found on Halo Waypoint.

Spartan Ops:

• Added the entirety of Halo 4’s Spartan Ops mode

Matchmaking:

• Made an update to make sure a match only starts when teams are even.
• Players will now receive a ‘loss’ when disconnecting before a round has ended.
• Made an update to include all split screen players in vote tally.
• Resolved an issue that caused players to become stuck “Joining Session.”
• Resolved an issue where players could be dropped from matchmaking after disconnecting their controller.

General Multiplayer Updates:

• Made additional improvements to Halo: CE hit registration.
• Made an update to the “Halo 2: Anniversary Career Progress” page to ensure achievements are correctly tracked.
• Fixed an issue where it took a long time to join players that are in a Multiplayer lobby.

General UI/Menu Updates:

• Made additional improvements to Roster update times.
• Fixed Halo 3 game type text when viewing saved data in “My Files”.

Halo 2: Anniversary Campaign:

• Fixed an issue where the ‘Black Eye Skull’ incorrectly prevented players from reaching checkpoints.

Campaign Playlists:

• Fixed an issue where cross-game playlists could fail to progress to the next level.
• Made several fixes to Campaign Playlist Carnage Reports.
• Fixed an issue where Halo 3 Cooperative Playlist progress would not save correctly when completing a mission.
• Made changes to ensure that Competitive Scoring and Timing are tracked correctly in Halo CE and Halo 2 Campaign Playlists.

Stats & Medals:

• Made updates to improve stat tracking.
• Fixed an issue where the “Steaktacular” medal would not be correctly awarded in Halo 3.
• Fixed an issue where the “Supercombine” medal would be incorrectly awarded in the Halo 4 Campaign.

Achievements:

• Made an update to ensure that the “Flaming Ninja Anniversary” achievement unlocks when prerequisites are met.

Control Layouts:

• Updated the Halo 2 “Boxer” Button Layout.
• Updated the Halo 4 “Legacy” Thumbstick Layout.

General Stability:

• Made several updates to improve overall game stability.

An interesting note that 343 also included about Dedicated Servers:

We’ve seen many inquiries about dedicated server support for Halo: The Master Chief Collection. Dedicated servers have been up and running since launch, and we continue to optimize and improve connectivity. The vast majority of games are being played on dedicated servers, but in the event that players cannot connect to a dedicated server, the lobby will stay together and the match will still occur on a peer-to-peer connection. Please be aware that you may connect to the dedicated server quickly enough that you won’t see the ‘connecting to dedicated server’ dialog. The absence of that dialog doesn’t mean that you’re not playing on a dedicated server.

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