That will Always happen the first time you install Flyff, before you use the FlyfH Patcher. *Remember to delete flyff.a before patching.
Open FlyfHPatcher.exe and click Patch, you only have to do this once. Wait for it to finish (it's around 15Mb). As soon as it is patched you'll have that file in your folder, along with all the others you need to play.
