I cannot change gamma in-game, it stays the same on all available options (very low, low, average, high, very high). It is the first time it happens after many years of L2 and all kind of clients and operating systems. I tried with both mark/unmarked "Don't change display gamma" before starting the game, it stays the same. My OS is genuine, all drivers are up to date, i tried re-installing L2 or deleting system folder and updating it.
Anybody else having a fix for this or encountered the same problem?