Well , did you try to update your pack to the latest rev ?
If not , update it . If you don't know how , let me explain you :
Backup your custom scripts and data, overwrite the .jar files and data folder if needed, check if there were updates on DB, update your tables, or remove them and implement the new sql files.
ALWAYS be aware of having backups of your custom information and your working DB.
Good luck , and if your problem still exists , report it to L2J Free forum.