I just successfully loaded data to http://usegalaxy.org, so the server is accepting connections. I used Filezilla, but the client should not really matter, even line-command will work.
Help for FTP: https://galaxyproject.org/support/loading-data/
Check the target server, your user/pass (same that you use to login to Galaxy email/pass), and that FTP (not SFTP) is used.
If you have problems after that, could you explain when and how the problem manifests?
Thanks, Jen, Galaxy team