After I ran the code i needed to talk to saint and when I did my quest just disappeared I did all of the previous quests on one character and the same with the Corridors of Time quest
I had the same bug as OP. I have done the following steps to continue the quest:
Attempt 1: Exit game, returned on same character, I did not get the quest step.
Attempt 2: Switched to the character that I have done the previous story quests with (saving Saint-14, giving him Perfect Paradox, etc), Saint-14 has the quest step for me.
Hopefully this helps others.
~cheers
*edit: word