YSFlight Headquarters

I know that, air.lst goes to aircraft and user files goes to user. I copy all the files into the right places, DAT. still cant load.

I recently downloaded the Ace Combat 3 Aircraft - update pack, and whenever I open YS it gave me error messages saying (this is just one of the error message) cannot load ac3ys/aircraft/af117.dat and so on. None of the planes can load. Please help me, how do I fix it? I really want to try out this p...