Pillar of Autumn Achievement in Halo: The Master Chief Collection

this one didn't pop for me but Halo did. say i'm at 100% unlocking... but hasn't unlocked.

343 said that they are working on fixing the problem with certain achievements not popping and should have an update out this weekend to fix it. My guess was that the achievements that didn't unlock for me were because the disc was still installing in the background when I met the conditions for them. As soon as my game finished downloading the achievements for killing a set number of characters popped after killing one of each character.

I think #2 is right, I probably did the same where I played the level before it was fully downloaded so there is an issue with the achievement being stuck.

I had the game fully installed and played the first 2 levels but no achievements popped. Unless having the bandana skull counts against me, because it says it has a 0 modifier, but it is just so damn fun zinging plasma grenades everywhere.

#2 - plausible though not the case for me. i had 5 achievements for CE glitch on tuesday and 4 of them popped randomly today while playing 4. this achievement being the lone hold out. the others didn't involve killing though. #4 - preorder skulls disable achievements so yeah bandana would prevent you from earning them.

I also suspect that the achievements that say 100% unlocking for me is because I started when it waz installing, it's a nice feature but i prefer to let a game install all the way before starting it, to avoid mishaps such as this, but i waz just so damn excited to start playing

Not all preorder skulls disable achievements. Only skulls that have a 0x multiplier disable achievements. Also playing this level while installing the game doesn't effect it either. It just has not popped for anyone, even though it says 100% complete.

Legendary Guide: https://youtu.be/95jf9oL2X2w