If you go to my profile on here, you can see I have beaten all the missions on Legendary, but only the Heroic achievement is unlocked for some reason…
I did this while offline, and had no internet. When I got back online, some achievements showed up, while this particular one and maybe some others did not…
If I beat any one mission on Legendary again, might that activate something, so the achievement shows up ?
There’s certainly no way in hell I’m going through every mission again. I just want a quick/easy fix if there is one.
Has this happened to anyone before, and 343 if you’re reading this can you fix my “yoink” …!? (:
Thanks
Yes this is my issue too. Except I did all missions while online, i also collected all skulls and Intels, I did not get the skulls achievements either.
Also, I repeated the last 3 missions, as well as a few others (solo legendary) and that did not help. Also tried a hard reset etc. I completed this a week or two after release, and the achievement still has not popped up.
It took a solid week before mine unlocked, they unlocked one at a time because I beat Heroic + Legendary in one go. And sometimes the achievements on the one are just laggy/buggy, in the days of the MCC one of the achievements took 7 months to pop after I unlocked it. Seven. months. Just be patient and it’ll eventually pop in 
> 2533274892914818;3:
> It took a solid week before mine unlocked, they unlocked one at a time because I beat Heroic + Legendary in one go. And sometimes the achievements on the one are just laggy/buggy, in the days of the MCC one of the achievements took 7 months to pop after I unlocked it. Seven. months. Just be patient and it’ll eventually pop in
Seven months? Wow…this sort of stuff never happened on the 360…
> 2533274808475903;1:
> If you go to my profile on here, you can see I have beaten all the missions on Legendary, but only the Heroic achievement is unlocked for some reason…
>
> I did this while offline, and had no internet. When I got back online, some achievements showed up, while this particular one and maybe some others did not…
>
> If I beat any one mission on Legendary again, might that activate something, so the achievement shows up ?
>
> There’s certainly no way in hell I’m going through every mission again. I just want a quick/easy fix if there is one.
>
> Has this happened to anyone before, and 343 if you’re reading this can you fix my “yoink” …!? (:
>
> Thanks
it can take a while to unlock, also it wont register till you go online. On another note, its not registering completion time from sword of sangheleos on, so you may want to play it again from there. This has been one of the easier halos so it shouldnt be too hard
> 2533274837877643;5:
> > 2533274808475903;1:
> > If you go to my profile on here, you can see I have beaten all the missions on Legendary, but only the Heroic achievement is unlocked for some reason…
> >
> > I did this while offline, and had no internet. When I got back online, some achievements showed up, while this particular one and maybe some others did not…
> >
> > If I beat any one mission on Legendary again, might that activate something, so the achievement shows up ?
> >
> > There’s certainly no way in hell I’m going through every mission again. I just want a quick/easy fix if there is one.
> >
> > Has this happened to anyone before, and 343 if you’re reading this can you fix my “yoink” …!? (:
> >
> > Thanks
>
>
> it can take a while to unlock, also it wont register till you go online. On another note, its not registering completion time from sword of sangheleos on, so you may want to play it again from there. This has been one of the easier halos so it shouldnt be too hard
Thing is, I did that and they still did not unlock…I believe it may be a server issue of some kind.
try going to misions, see if that shows completed. If not but your game shows legendary, play the ones that show as blank on easy mode, worked for me right away. I f I said this right should unlock if easy is played online. no skulls used right?
If you go here, whilst it shows them all with the legendary symbol, all the levels after “Re-union” (Save “Before the Storm” seem to be uncompleted.
You might have to re-do them again 
If you do want to do them again I’m sure there’s loads of easy legendary speed-run guides for the game now, so it should be easier. For example you can skip the three warden fight at the end of the penultimate level.