Some Halo 3 playlists (notably Lone Wolves) get stuck in the "Loading" phase, with an error message saying "Information could not be retrieved from Xbox LIVE". This prevents players from selecting a different playlist: you have to join someone else's session who is already on a different playlist. This has been going on for several days now (at least since November 30).
With the servers going down permanently in just over a month, some players would like for the game to be to be playable in the meantime.
You would want to he d on over to halowaypoint.com and make a post there. Bungie is no longer a part of supporting the halo franchise, that is currently 343i's responsibility.
The Halo franchise is managed by 343 Studios and not Bungie. Halo support should be directed to their site at https://support.halowaypoint.com/hc/en-us