Guild Wars 2

Every video I’ve seen people go to all 20 instructors and answer questions. When I get to the some of the stations they are empty, no instructor/no color, just an empty stand. Is there something I need to do to make them reappear? Or is this bugged?

From the wiki for Rata Novus Instructors (it’s way at the bottom):

Only available when the outpost reaches level 2 or above when the waypoint is uncontested.
Instructors vanish when the Legendary Chak Gerent event starts. The opening in the wall to get to Zinn’s Research Supplies also closes then.

I read the wiki. That was not the problem.

I was trying to explain that one instructor was there, next was not, the third was NOT, 4th, 5th were there, 7th was not, etc… That’s what I was confused about. Two stands right near each other and one is working and the other is not. Broken/Disabled stands mixed in with working stands.

Got the same problem, anyone found what it is, the instructors look like this:
http://i.imgur.com/OVuvqL5.jpg