Ok I have no idea what that error is specifically, and I don't want your $20. But here's my advice on getting EQ to run in Linux.
First, I don't use wineskin or play on linux or any WINE wrapper; I just use wine. I run a shell script that starts it like this:
cd /home/me/Desktop/EverQuest/
wine eqgame.exe patchme
(Yes, I keep my EQ install on my desktop ... makes it easier to get to logs and screenshots that way
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If that command doesn't work, I play around with the options I get when I run winecfg. Mostly I play around with the OS options (Windows 98 didn't work? Try Windows NT! And so on), and stuff like whether wine runs in an emulated virtual desktop or not or whether wine manages the windows or not. In my experience if you futz around with those settings and the OS settings eventually you can get rid of errors like the one you're seeing (but no guarantees).
If you can't, I'd install the latest graphics drivers (probably the non-free ones, but depending on your card the free ones might be better; again you'll have to experiment).
Finally, once you get the game to run, you might have issues with no servers at the server select screen. A VPN seems to be the only fix for this thanks to Rogean's latest changes, but previously a script called P99 Middleman D used to help also (and might still, just not for me).
If that doesn't work I'd post back here or try searching the technical forums (you're certainly not the first to run Linux and want to run P99).
Hope that helps, and good luck!
P.S. There's also
http://wiki.project1999.com/EverQuest_in_Linux_Guide, but I can't speak to how relevant it still is.