I have trouble with the marathon achievement!
One day I was going through The Ark, The Covenant and Halo to get the Marathon Achievement, but when I got to the last terminal on Halo and accessed it, nothing happened... What am I doing wrong? I tried accessing it multiple times but it still didnt work! And yes, I have accessed ALL terminals, I have the Halo 3 Guide Book so I know that I accesed all of them.
So, what am I doing wrong??