Gamma slider isn't working

[KcindX]

Everytime I go into the game I can't turn up or down the gamma, I've used the tried setting the slider to both the far right and far left but the screen doesn't change at all. It seems to be stuck at all the way down as the game is very dark.

It's worth noting I have every major expansion and I've tried reinstalling to no success, also I'm on Windows 8.

 

[AndrewT]

Has this always happened ever since you've had the game, or only since what change or update?

Does it happen with Eu4 or any other game?

Please post a dxdiag.txt (you can delete everything after the end of the "Sound devices" section for brevity) and your Documents/CK2/settings.txt. From your Documents/Paradox/CK2/logs/ directory, post system.log . Open setup.log in notepad and search for 'checksum', post that line only here too please.