Ruby FTP 504 Error

when i try to put file onto 开发者_如何学Pythonserver i get this error "504 Command not implemented for that parameter".

I'm logged in, can change directory, get current directory, but when i use put() or list() i get error.

Anybody know what's the problem :?

It turned out that the problem lies with the FTP server that doesn't allow to use Active Mode. Need to use Passive Mode.