I've gotten this a few times now...

It happens at random times and has been happening ever since the patch. :/

Same and this horrible epic lag i've never ever had before even on lowest quality. I thought it was the JQ in kaede castle because thats where i get that error all the time.

Oh, that. Yeah, that happened to me once. Right when I first logged in after the patch. Since then, I've not had that issue.

Same here. Except it randomly closes for no reason and the box doesn't show up.

I really have to wonder what the heck they did. I've heard a number of people complaining about issues they hadn't experienced before this patch like this that I've been experiencing since .88 and yet most of my issues with DCing have personally gone away with this patch (assuming still being forced to log in through the website). I can't vouch for bosses though, but as a Vista 64-Bit user I haven't DCed or lagged at all since the patch (assumed logging in through the website).

Maybe it was just a day full of luck? Maybe they are playing with buttons and somehow fixed one case of errors and opened up 7 new ones? Who knows. I do hope for everyone to be able to play normally soon though.

EDIT: Spoke too soon. Got this finally after mass log-in log-out for the daily gift quest. Happened right after a log-in and was clicking on the light bulb for the quest.

EDIT2: Despite what I said in my update, it still is a heck of a lot more stable for me now. I tested minimization, window mode, switching users and afking all night; none of which would keep the game running before for me; and now I have no problems with them.