the "very" last chance?
start a support ticket. Let them help you troubleshoot the issue.
Or try tuning down all your graphics settings just for the instance. Sometimes the requirements are heavier for stories, especially cutscenes. (I had a friend who had a badly-built computer who only ever crashed in story instances; they were fine in WvW zerg fights.)
John Smith: “you should kill monsters, because killing monsters is awesome.”
switched to fullscreen instead of windowed fullscreen, worked
Ah, interesting. Glad that worked.
Do you have your frame rate limited by the game by any chance?
John Smith: “you should kill monsters, because killing monsters is awesome.”