Okay so I've installed the mod tools and patched it with all the available patches, I'm running 1.7 WaW but whenver I use UGX script placer and build the files I get some weird error in this file mods/_mods.gsc but the thing is this file doesn't exist so how can there be an error inside it?

we need a little more information. can you post screenshot of the problem.?

when do you get the issue. while using the script placer or when you compile you map?

have you made sure you have installed all the modtools and patch correctly. make sure to follow the UGX tutorials.

while your in the tutorial section read the getting setup part.  make sure you follow all the steps. once your done you can start mapping.