AC Brotherhood - Completing all of subject 16's puzzles

I completed the game first before I completed all of Subject 16's puzzles. When I run around on subject 16's secret level I reach a dead end where nothing happens and there is no further place to free-run to.
Is this meant to happen? Or have I done something wrong? I have to re-load my last save to continue from where I left off in Rome.

Solution 1:

I too completed the game before solving all his puzzles. You should be able to go through 16's secret level anyways, but keep in mind it is a maze. So if you reach a dead end, you'll need to find another route. It took me a few tries, but I finally reached the end.