I've followed the instructions as followed for installing this (Copying everything from the Windows version and then moving the necessary files to make it run natively) and then double clicked on the file to run the game, bur then the strangest thing have happened, when I was checking up on the mod menu, it's been clean like when you run the game for the first time, what's worse is that there's no custom models and voice packs at all.
But then, I come up with a conclusion, when I was typing preferences in the game's console it came up with this message..
And it made me think "What if I placed the .u and .int files that the custom mods use in that directory?"The advanced preferences window is not available on
your platform.
If you want to modify advanced game settings, then
please close the game and edit the following ini files:
/home/UserNameHere/.utpg/System/UnrealTournament.ini
/home/UserNameHere/.utpg/System/User.ini
So I did exactly that, copied all of .u and .int files for the custom mods to that directory, run the game again and lo & behold, it works.
I hope this would help out those who want to try getting their custom mods working in their Unreal Tournament. And if it did work for you, you're welcome.