This is a tough problem. There are 2 reasons why you could get this message.

1. You dont have a legal version of Sof2, with a legal CD key. When having this problem, there are 3 things you can do:
- Play on unpure servers only but then u wont be able 2 play @ CF server or S&B server.
- Buy a legal Sof2 game, with legal CD key, but it will cost u €5.
- Generate keys, (download Key Gen) untill u find one that works as there are some ppl who cán play with illegal keys.

2. Your game folder is invalid, that means it contains files that punkbuster does not allow. It is impossible to search your entire sof2gold folder and to delete those files. The easiest way is 2 uninstall sof2 gold. Once you uninstalled the game though, you will notice that those mods & skins are still in that sof2gold folder; Sof2 has not uninstalled them with the game, as they arent part of it in the 1st place. It is your task to delete everything that is left, in that sof2gold folder, so you end up with a clean and empty sof2gold folder, ready to install the game again.