I end up with the same problem Somnus. I was able to get through the first 2 instances, but the 3rd (Echoes of Ages Past) outright crashes my client every time I try to load it. It seems like a large amount of other people are getting the same problem.
see below:
https://forum-en.gw2archive.eu/forum/support/bugs/Game-Crash-Norn-Story-Echoes-of-Ages-Past