Me and one or two other people here on the forums have had this happen to them yesterday as well, and after spending all yesterday looking for a solution I can say that this is an error on SE's end.

The error only applies to that character. I can log into a different account from this computer but my main gets hit with a 30002 error every time after character select so there is nothing wrong with my internet connection. I've seen people say that if they create a new character on that same account they can play the new character without any issues, so for whatever reason its character specific... Whats worse is that I've found posts about this dating back as far as 2010 with no solution ever found... So either our characters are rendered useless because of an error on SE's behalf or because of the number of people who are all having this error at the same time they look into it.

Just wondering, when did you activate your account? I activated on the 30th and my character didn't get moved to its new server till the 5th, where I could play fine till I got this error yesterday. Just want to see if there's anything in common with people who are getting this error.