MCC REACH CAMPAIGN ACHIEVEMENTS NOT UNLOCKING

This is still somehow an issue. I completed "Did You Major in Marine Bio" and "Classic Completion" months ago and countless times since then to try and get them to unlock. I've had an open support ticket for months with a bunch of useless support replies...

Solved. (At least for my own case)
Posting on all the threads I can find on this site for convenience.

Issue:
Majority of achievements unlocking but nagging few aren't (heresy will stay your feet/two corpses one grave...). Tried telemetry... host files... signing out... windows firewall most of the advice that you'll readily find and nothing worked until the below.

Solution:
Found on https://www.trueachievements.com/forum/viewthread.aspx?tid=1149222&page=2

Post by Tarvu as follows:

Ok so if you're on Steam, you don't have to uninstall.
1. Disable Steam cloud synchronisation for the game (right click in library, properties, updates)
2. Delete the folder titled 976730 in your steam profile userdata folder located in:
C:\Program Files (x86)\Steam\userdata\3. I also deleted the folder MCC located in:
C:\Users\[YOUR WINDOWS USERNAME]\AppData\LocalLow

BACK TO ME:
I did the above and then played through again. Both achievements have unlocked so I'm pretty sure everything is now working fine. Just to clarify they didn't pop up as soon as I started the game, I had to actually do it again. But this time they were correctly tracked!
I have kept cloud syncing off as the servers seem to have stored everything anyway, just had to reconfigure my controls again.Good Luck!

I beaten Halo 3 on Legendary in one day, days ago and yet still haven’t unlocked the achievements for completing it. What the -Yoink- MCC!? I didn’t go through all that grind just come out empty handed. Patch it and give me my achievements because it clearly states every single mission is completed on Legendary

Yet they're still working on other larger projects such as porting Halo 2 before they even get the achievement system working. Many issues including campaign achievements popping out of order, such as mission 1 completion rewarding me for mission 4, and so on until it loops back around, that issue somewhat solves itself as completing the campaign does in fact give you these achievements in the end, albeit out of order, there are other issues of note also.

Such as the achievement "No Picnic" it simply wouldn't happen for me, same with the achievement where you must kill 7 Moa on winter contingency, did it with all difficulties, all skulls, even did it during my LASO run, didn't work, can't forget the "All According to Plan..." achievement either, which is to kill all the enemies at the start of the Truth and Reconciliation on halo CE without being detected, did it numerous times also on all difficulties, still didn't pop. My own research on that one told me that 343 is basically saying it's not bugged, it's just super hard, but my video evidence begs to differ, last enemy was a sleeping grunt, I ran all around that area, but the very moment I killed the grunt, nothing happens, which being sleeping basically proves I was undetected, but upon killing him the music starts and the other enemies run in, and no achievement ever pops. 343 says there's no issue, but sorry to tell them ignoring an issue doesn't mean the issue doesn't exist.

No wonder more and more people are unlocking these specific achievements by... well, "unauthorized" means, but if the devs wont fix it, modders who despite not being paid will always find a way to fix a developers mistakes, especially when the developer sticks their fingers in their ears and pretends they can't hear us, and resorts to copy and paste replies to our ticket submissions, no matter how many we send in, they'll continue to persist there's no issue. I've named this tactic "the Trump approach" because their handling of in-house issues basically copies Trumps approach to being president lol

Marcus Seth wrote:

I've recently completed Halo Reach MCC on Legendary difficulty solo. However the missions."The Package" and "Exodus" still remain incomplete. I decided to play the package again on legendary difficulty, completed it, got to the end of the cutscene, still no achievement.

Really hope this gets fixed soon, honestly quite annoyed that I replayed the mission only to get nothing out of it.
Whole mission was played in one shot without stopping and barely any deaths. Also if I did not complete the mission, how would it be even possible for me to progress to the next few missions and complete them solo?

same here but all my missions say completet solo and coop both on legendary everything seams to be fine the legendary playlist is completet i did it solo nothing is wrong but the arcivement isn´t unlocked :(

Lurch Skywalker wrote:

I am still having an issue with the Par Time recording for "Wait How'd The Ship Get There". This is the last one I need and I have the stage down to about 8 minutes and it still isn't rewarding. This has been a known issue since the game released on PC. Also a friend of mine is still having issues with "Two, Corpses, One Grave".. Can you please fix this already, or atleast reward us our achievements we have accomplished dozens, and dozens of times now?

You don't need to post the same thing multiple times on different threads. If you have an issue, you can either create a thread of your own or submit a ticket to the Support Team.

I'm currently playing Halo 2 on Legendary, and yesterday I've finished the Arbiter mission Solo. However, I didn't receive the achievement for completing the mission. The game itself shows that the mission was done in Legendary solo, so my question is: when I finish the entire campaign, will the legendary completion achievement pop up or will it be blocked?
I'm thinking about doing the mission again on easy just to try unlocking it again, but I'm not sure if the game will count the legendary run done before as a valid run.
Besides, this particular mission is luckily easy to beat, but if the same problem happens in the gravemind, it will be very frustrating...

This post has been edited by a moderator. Please do not purposely bypass the word filter.
*Original post. Click at your own discretion.

And here we are on a post made a good bit of time ago, with zero progress or even a "we're looking into it" update. The mission Sacred Icon on H2 is a pain, finally got through it on legendary in under 15 minutes, no achievement, and looking in leaderboards, it didn't even track the time, it still says under legendary that there's no entry for time, even though hovering over it in the mission select shows it's been completed on legendary. I don't want to go any further until I can get this, so I can unlock them in order, and it's really irritating.