So when I hit lvl 34 as a Draenei warrior,I wanted to do the quest for berserker's stance.I took the quest The islander,and went to the island near Ratchet.But when I proceeded to take a chain quest after the Islander,to summon that Big Will guy,my game crashed.I relogged,and it crashed again.After the quest failed(it has timer of 5 minutes) I logged in again without any problems,but again I took quest and game crashed.When it crashes,I literally cant do anything,I have to restart my computer.I can still hear the music from logon screen but I can't do anything.It happened 5 times already and it's getting frustrated since I really want to do that quest.
If you're using the addon QuestHelper, stop using it on timer quests. It crashes the game and we can't do anything about it unless we fix the addon itself.
Issue is really Questhelper...same bug i was get in durotar with timed poison quest and timed in crossroads. Now i use Carbonite, and everything is okay.