Guild Wars 2

Went with a group of 5 to get ‘Nary a Pitfall’ ach. Two people had it on thier bar as an available ach, I did not even though I have not completed ach yet. The requirements for the ach were met and the ach was not awarded to me or to the people who displayed that ach as active for the mission.

According to Dulfy, you have to wait until the very end of the instance for it to be registered.

“You cannot get the achievement until you return to Taimi and listen to all the conversations until the very end of the instance after you have talked to Kasmeer. So once you got all 3 items, keep avoiding traps on your way back to Taimi. "

Did you fully finish the instance? If not, that’s why no one got it. Similarly, if someone ran through a trap on the way back to Taimi, that could also be why no one got it.

As for why the achievement icon wasn’t on your bar: have you already completed that living story chapter on that character? If not, you need to do that whole chapter on that character to unlock the achievements for it.