Try making a clean reisntall of the game and then install the mods, obviusly first delete every mod then uninstal HOI IV, for that go to the place where HOI VI is insalled and delete the folder then go to steam and unistall, why not only unistaling from steam? Because if you don't do it in that way steam will insall any folder that you've changed or the mod changed, so is better to do it like this trust me.