Disable IPv6 In Filezilla 2012-04-05
If you are getting an error message about Filezilla Server not being able to open some ports for IPv6, you can solve this by

- Browse to your Filezilla Server installation directory
- Open FileZilla Server.xml with a text editor or XML editor
- Near the bottom you'll find "Disable IPv6"
- Set it to 1 (instead of 0)
- Restart the Filezilla service
- Stop/Start the server with the management interface to see if the error is gone