Can't run ekRO (Ragnarok Online)

[18MW]

I've been trying to run a private server client on my computer and I get this error when I try to run it.

I'm using Wine 1.2.3 on Ubuntu 11.04. The How-To's on App DB can't help me since I can't even get to the log-in screen.
I hope to find a solution here, thanks!