According to 343 professions, Achievement support “will vary by topic especially since matchmaking is required and challenges are no longer obtainable.” The culprits who lose record support are Hollow: Reach, Hollow 4 and Hollow 3. The chart above indicates that achievements for Hollow 3: ODST, Hollow Wars and the Hollow: Spartan attack should not be compromised, while the achievements of the Halo: Combat Evolution Anniversary Anniversary will all be opened offline. To be on the safe side, it is worth operating through all Xbox 360 online-flagged Hollow achievements.
All of these games are listed from the Microsoft Store, so if you do not play these titles and want to start your way through their record lists, you should find a physical copy of each game. One side is, in particular, the Hollow: Spartan attack (Xbox 360) One is a partially stopped / unattainable achievement And not physically available.
343 Industries says online services will be discontinued after December 18, 2021. You have a year to open them before any achievements of these games stop.
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