Johan,
Your company Ashram Nieuwkoop has 904 Ruckus Premium support. You can contact us by phone, chat, or create a support
case thru the portal, and we will be happy to provide firmware and tech support.
The FTP server is typically only used by tech support to provide patch files.
The Support portal Downloads page, has a link to 9.9.0.0.212 firmware for ZD3k here:
https://support.ruckuswireless.com/software/672-zd3000-9-9-0-0-212-ga-refresh-software-release