I'm pretty sure I created my worgen back on v5, and I think I know what quest you're talking about (can't remember for sure, though), but I've never had the worldserver crash because of it.
Are you running the worldserver.exe as admin? That, or something to do with the compatibility could be the problem.
Anyway, if you can't figure out how to keep the worldserver.exe from crashing, just type in these following commands while in game to get around the quest:
Woo hoo. Solved, thanks man. I wasnt run the worldserver.exe as admin... crap. I didnt thought how much it matters. Running as admin = there isnt problem with scripted quests, no crash. And i know much gm commands so that would be plan B