I recently played through Final Fantasy 7 Crisis Core Reunion and encountered a bug in the game. Once I got to the Portal of Severance I was unable to open the gate despite having found all of the goddess materia. I searched around and sure enough, I found a few instances where other people ran into the same issue (apparently on the original Crisis Core).
Thankfully I had a backup save in Gongaga and retried, this time with no problems. The difference is that this time I simply got the Goddess Materia without doing anything else. So I’m pretty sure the bug was due to my doing things out of order last time around.
Last time around, I had grabbed a few Goddess materia, then spent some time exploring Lake of Oblivion, then spent some time in The Howling Fang and defeating the Behemoth King. All the while I was sporadically getting new Goddess Materia and adding them in the Portal of Severance. Oh, and on top of that, I was randomly going on Missions.
So I’m pretty sure this ‘broke’ the code as it were.
The take-home lesson is: if you run into this, hopefully you have an extra save in Gongaga!