I got onto Halo 4 to play multiplayer last night and when I got on I found out that my campaign progress was deleted and my multiplayer character was reset.
These are the details:
I launched infinity war games and it played the into video and acted as if this was my first time on it. When the video ended I checked my Spartan and found out that it was reset and all of my armor and emblems were re-unlocked. Each armor and emblem had a star next to it as if I had just unlocked it. I had to remake my Spartans armor and emblem. Then I found out that my load outs were reset and set to default, so I had to recreate them also. At this point I was upset so I went to check my campaign because this has happened once before. When I checked my campaign I discovered that it saved the mission I was on legendary solo but on the mission list the only available mission was prologue.
Is there some kind of fix for this because it upsets me. I am a die hard halo fan but this glitch sucks. This is the second time this glitch has happened to me and it is not good. When I re-unlock the missions they do not recognize that I have played them before and act as if I have never played them. I was close to the end of the game and now if I complete the rest of the missions I will most likely not unlock the legendary solo achievement.
PLEASE HELP IF POSSIBLE
The glitch started occurring back in Halo: Reach and the cause of it is still unknown. When it happened to me in the past, I deleted my profile from my Xbox and redownloaded it and to this day it still hasn’t happened again.
There is no way for you to get your Campaign progress back other than replaying through the whole Campaign again 
I advise you delete your profile & redownload it like I did and hopefully it won’t happen again.
You may still get the reward by the way via waypoint but no achievement. Checking your waypoint it shows Missions 2, 3 and 4 you have done in legendary on solo.
So you may get the waypoint reward via it, but I don’t know if you’ll get the achievement or so on.
But I don’t know how to really help in honesty.
> You may still get the reward by the way via waypoint but no achievement. Checking your waypoint it shows Missions 2, 3 and 4 you have done in legendary on solo.
>
> So you may get the waypoint reward via it, but I don’t know if you’ll get the achievement or so on.
That’s a good find, and though I’m not sure if it’s correct, it very well could be. Rewards like armor are given through Halo’s stat-tracking servers, whereas achievements would probably be tied to locally-stored progress.
> But I don’t know how to really help in honesty.
In Reach, deleting and recovering one’s profile could sometimes allow one to get an old (pre-data-loss) backup of that profile data from Xbox LIVE… But I haven’t heard of this being successful as often in Halo 4. :\
