Whenever I want to add something to an .iwd file in the main folder -> "access denied" or it just doesn't work.

I tried it with 7zip and WinRAR.

I also gave myself adminrights for that folder and/or file.

Why don't you create z_name.iwd instead?

 

Just use winrar to compress 'images' folder for example and save it as zip. Then rename it to z_mod.iwd or whatever and place it into /main

I want to add custom skyboxes to my game. Therefore I have to add several files to some .iwd files, which doesn't work