Guild Wars 2

I was attempting to get the In tune, and No More Tricks, Scarlett achievement.

Whilst doing so I got hit by a lazer without their being any pre warning. So this achievement failed.

I have also defeated this Prime Hologram from start to finish around 3 times (and obtained chest) leading me on to Scarlett yet the achievement One Step Closer is still locked on my achievement list.

you say no pre warning on the lazer, you mean you cant see the big orange lines on the floor? this is the first person ive seen say about this issue but I do know some colourblind people cant see the red aoe rings, maybe its something similar.