You can try updating your graphics drivers if they aren't up to date, verifying game integrity, or just flatout reinstalling the game through a clean install - meaning finding instructions to clear out all TU files.
Also, looking for that "RawChannel with write buffer..." problem I found a bunch of emulation problems, that is if you are emulating Windows OS to play this game.
Very weird question, are you playing TU with a emulated Windows OS on a Mac? I found a thread saying Wine's Mac driver isn't supposed to support an emulated desktop.
Another potential fix, if you're on Ubuntu, is to update some libraries and graphics drivers.