-Did you properly unzip the downloaded archive? Make sure everything is in its proper place.
-Did you put a shortcut to the client onto your desktop? Right-click onto the shortcut, open Properties and check if the proper path of your Illarion directory is set there.
I'm having the exact same problem right now. Damned thing is not responding when the screen is black, too. I have all the files extracted in the right folder and I have no shortcut for Illarion on my desktop, so there are no path problems...
Im getting the same problem. I just started playing today and the first time I logged on everything was fine, then later I tried to log on and I just got a purple screen, and everytime since that I've tried theres been the same problem.