I’ve recently encountered repeated crashes with the error message “Memory at address <8 digit hexadecimal number> could not be read.”, which started with the new Sept feature pack. These crashes (when they happen) always occur:
- After I click log-in, before the game launches, or
- while loading into Lion’s Arch (never tried other maps)
When I get an error at either 1 or 2, I’ll keep getting that error at the same time if I launch the game repeatedly.
Workaround
I have found that deleting the local.dat in your appdata/Gw2 folder completely solves the errors, with the caveat of completely deleting all your settings and downloading ~3-4MB for a fresh loadup. What I did was to change my settings in-game, exit, then rename local.dat to local.dat.backup. I copy that back whenever I get issues again. Note that I only tested this when the message specifies “App: Gw2.exe”. I have seen (in other online forums) “memory could not be read” messages point to the graphic driver’s dll etc. Also, this is a workaround, not a solution, and I hope that it can be fixed soon!
Hope it helps someone! I’m just glad that my memory is not corrupted. My apologies for the disemvowelment in the topic title, there is a 45 char limit! 
P.S To any mods, I submitted this crashes against general guidelines only because I had a potential workaround which I wanted to share, and that this problem seems to pop up on and off over the months, for some even before the feature patch. I hope you can keep it on if it’s helpful!