I've the same problem:
Today I had problems to call my retainer. I called a GM and it do something and... I cannot see my retainer anymore. The GM said to restart the game. I restart the game (logout correctly) and now I've the error:
"An error has occurred on the game server. (30002)131644XXXX,30099561,5"

Everytime I try to log with my PG I get this error.

I tried:

Another computer, my PG: same error;
Another computer, another PG (another account): no problem;
My computer, my PG: same error;
My computer, my account, NEW character: no problem... i can log in...

So the problem is my main character...

I had an online chat to solve the problem, but the agent that answer me escalated the problem, because he was not able to solve (and find) the problem.

They will send me an e-mail when (If they can solve it) the problem will be fixed (I think that the GM done something to my profile account in the game server, but I'm not sure

I know only that the problem born only after the GM done something to my retainer and restart the game.

I hope to wait only few days.......