I honestly don't even care about Guildwars at this point; I just want to be able to at least access the other content.
No other game, including Knights and Dragons previously, required this sort of shennanigans; it also has been tried by yours truly a number of times today to no avail.
I don't even see why this is hard, I'm crashing repeatedly EXPLICITLY when you attempt to load a notification window.
I gave this suggestion in a support request, but I'll simply put it here too: disable the notifications. No pop ups regarding guild wars, or that my guild is engaged in a war, or the screen that we won or lost a war. They do not help when I can't get into the game.
Not only that, it would cut a non-trivial number of the requests to your infrastructure, which might actually allow the game to be playable for a non-trivial amount of people more. You cannot make any revenue on this game if people can neither buy gems nor watch videos, and I and apparently others aren't even getting that far: the only thing I can do is login, click OK on the armor crafting notice (and that screen works just fine, yay I can create more Basic Fire armors) and then soon as I exit it waits on pulling up the notification and the client crashes.
This seems really simple to me, just disable that functionality as it's not critical to the game play.
Edit: here's a suggested recompense you should consider: for every half hour lost to this, you should offer an equivalent number of gems to the purchase of Epic Boss energy equal to the amount of time lost. That's the major impact to my own progression right now, I've been able to get in and hit the boss a whopping one time today since the release of Guildwars.