Invisible symbols in the Boston Gate Lantern Underground puzzle

I am stuck in the Boston gate magic lantern puzzle in the PC version of Assassins Creed 3.

The one I'm talking about is the one farthest to the left. I know how you are supposed to solve the puzzle, the problem is I can't seem to see the symbols. I have all the other doors unlocked except for this one.

I mean instead of seeing this:

I see it without the symbols. Pretty much what the door used to look like, almost like this

but zoomed in and with the directions like you would normally get

Is it a glitch? If so, what can I do about it?

4

1 Answer

I encountered this once on the PS3 version. Rebooting my system solved it for me. I'm not sure how saving on the PC version works--you might want to try leaving the sewers, saving, rebooting, then going back into the sewers to see if that fixes it.