To avoid connection issues:
Before you download and install the raidfight folder, be sure to disable active scanning of your antivirus program due to the fact that some antivirus see the codes in the files as trojans. This is not the case!
After the download, install the raidfight folder into your Lineage II root. After that try to place the entire raidfight folder in ur antivirus exception list. After that you can turn on your active scanning and enjoy this wonderful server.
In the case your antivirus doesn’t have an exception list or whatever it’s called (for example McAfee), disable active scanning before you run l2.exe inside raidfight folder.
If you get a pop-up saying the location of the file is missing, then go to your antivirus and look in quarantaine and recover the files. This only counts when your antivirus doesn’t have an exception list.
xD