
Originally Posted by
Johnny Knoxville
Happends to me aswell
its not texture modding files tho 
Don't comment on things when you don't know what you are talking about.
OP you can either use your backups, which you should be making, or re download the game (if on aIW). If you have Steam you can just verify your files and it will download only the broken IWD for you. But it will also redownload all the other ones with mods in it so be careful.