Start S4 as admin and close all unnecessary programs.
I had the problem today too; and it worked afterwards without changing any file in the S4 Folder.
In the worst case scenario, reinstall the game.
/closed
File is Changed - Xtrap.xt Meldung 12/22/2010 - S4 League - 21 Replies Bei mir kommt immer die Meldung :
File is Changed Xtrap/Xtrap.xt
(ich hab keine hacks an)
Was machen?