Halo 3 ODST achievement problem

Me and my friends have played the whole thing on legendary and we have to do one mission over and over again.
We always do it in 2 parts and we don’t get the heroic and legendary achievements.
Does anybody know what is going on??? I am getting pretty mad

I think I know what the problem is. Rather than starting a new campaign, you start with “replay mission”. In some way, you are probably skipping the Mombasa Streets section. This campaign is unique, in order to get the achievement, you must start from the very beginning, and you must resume your solo game when you return.

Overview: Don’t select missions by the Replay Level feature, start from the absolute beginning and continue your game from the precise moment/area you saved the game.

> Me and my friends have played the whole thing on legendary and we have to do one mission over and over again.
> We always do it in 2 parts and we don’t get the heroic and legendary achievements.
> Does anybody know what is going on??? I am getting pretty mad

Have you done ‘Mombasa Streets’ on Legendary, I believe all you need to do is just load it up on Legendary, start the game, wait a moment or two after it loads and end it.

That is the main cause for this, just like watching the ‘Arrival’ cutscene on Halo 3.

It said we have done data hive on normal and we did it 5 times but we always had to leave off on a checkpoint because I had to get off.

I had that same problem at one point but i eventually figured it out. I can’t remember how sorry

> It said we have done data hive on normal and we did it 5 times but we always had to leave off on a checkpoint because I had to get off.

You must complete each mission in one continuous playthrough. Can’t save and quit mid-mission.