This is due to a bug. In the flyff folder there is a small file
called flyff.a. It is about 5 mb and is a A type file. Deleting this
resolves the issue and doesn't effect the gameplay.
With the patcher, MyNewNeuz and loader files remember to extract to: (windows)
C:\Program Files\Gpotato\Flyff
This might seem like an understatement but it is a common problem.
When you load your patcher for the first time, it will need to update.
Click on Start and it will download the required patch files.
Remember to be on V11 for this server and follow the download guide thoroughly