every time i enter to a world the Gamma override is on, even when it says "off". When i press the hotkey of gamma it changes from off to on and then if i press it again it turn of as normal.
and when i press that key fast enough it crashes the game

The gamma value is saved in the vanilla options.txt file, and it's possible for the tweak to get out of sync with that. I think it happens if the gamma tweak is toggled on or off without going to the vanilla settings menu after that, maybe? I probably need to add a call to the gamma tweak toggle to also cause a save for the vanilla settings to try to fix this.

What is the crash you get? And do you mean just quickly toggling gamma on/off in succession?