[Crashes and freezes during 2nd half of Labyrinthine Cliffs treasure hunt]

I'm having the same issue.  The game freezes abruptly, no warning or problems beforehand, floating around in my skimmer in phase 2 of the treasure hunt and then locked.  The music is still playing, and the rest of the computer is still there; I can ctrl-alt-del to open task manager, or alt tab to select other things, but I can't actually bring any of them to the foreground to use them.  The still image of GW2 dominates the screen and can't be closed, forcing me to restart or sign out.  I also had this problem at Tequatl a couple weeks ago and have been scared to try it again, apparently for good reason if it's the same.

[[Bug] Junundu Master Certification (cadet training course)]

I had a problem with this too; I was only able to hit two targets out of the eight, and the others were untouchable. I spent five minutes at the first target alone using both my melee and ranged wurm skills from all different angles but unable to scratch it. I was the only player there and this was the first run, so it couldn't have been other interactions breaking them.