This isn't a terrible bug, it's probably just an issue with my video card, but twice now I've cast pneuma in amatsu dungeon and most the screen turns white until I relog.
I'm not asking for any sort of fix, I just thought it'd be interesting to show.
Hmm that's happened to me on other servers as well. First time though was during a Christmas event, so I thought the GM's did some reprogramming to put snow on the ground. Maybe god decided to show you where the spirits you were killing were going?
It's a problem with your video card reading too many things (skills, classes, movements, etc..) from the server at once. Regardless of the type of card you have this can happen to anyone. If it stays that way the fix is to just reload your video card drivers other than that it's as simple as Joe said, just re-log.