If like me you are trying to use this mod with a monitor that does not support a resolution of 1920 by 1080 (HD) you will likely run into an out of range error or simply get no image at all.

If you navigate to the default install folder

C:\gog games\doom3 phobos\tfphobos

and look for the file

doom config (open with notepad etc)

then look for the following two lines

seta r_customHeight "1080"
seta r_customWidth "1920"

you can change these two values to match your native resolution and the game should work.