Oh thanks a bunch for going out of your way to help man!
So, could you make a script - put it on an object in the scene, and put this line in:
void Start(){ Debug.Log(Application.dataPath); }
Then build and run a Linux version and tell me what the Player log says. I don't know how much you remember about Unity but you can find the Standalone Player log in the console tab
[Edit] Ah, I see you make games so I'm probably over-explaining this 😄
Thanks Timeearl!!