Achievement App Bugged/ Won't Open

I am also having this problem. It started this morning when I woke up. The achievement app won't open and no achievements are unlocking. Also they won't load when opening the smart glass app. This is super frustrating. I believe it's the same error code
everyone else is getting which is 0x87c40011

I already had games that the achievement bugged and enabled more than a month later, maybe it is some problem with the achievement, see if others are experiencing the same problem with this achievement in specific, what percentage of people have made this achievement?
Check the TA if there are any tips, first install the service app, with this achievement open up to the Y, this will direct you to this achievement and how to do it, good luck!

Lots of bugs in the achievements on this game. I have the ultra edition and some achievements open early, while frequently rewards (unlocked colors) don't open when the requirements are met.

I'm having the same issue. I get the error code 0x87c4000d when I try to compare achievements with friends and I get the error code 0x87c40011 when I try to open the achievement app ( which won't open ). It's definitely got nothing to do with Halo MCC as
I don't have it

Hey everyone!

I'm sorry to hear about what you're experiencing with the achievement app. Thanks for posting up the detailed information! We are actually tracking this issue over in this thread. Head on over there to check for any information or updates. Thanks!