FTP connection WebPlayer SecurityException: Unable to connect, as no valid crossdomain policy was found

Hi, i am creating WebPlayer game where you can save and load based on your login/password.
I need to connect to my Ftp server that is secured with login and password. crossdomain.xml is included in the root folder of my server.

  webClient.Credentials = new NetworkCredential("username", "password");
     
        string js = webClient.DownloadString("ftp://ftp.domain.com/saveData/saveData.json");
       savingData = js;

I always got an SecurityException: Unable to connect, as no valid crossdomain policy was found.
if i change the url to an classic webserver without any security with the same crossdomain.xml file it works fine. I was also trying FtpWebRequest methods with the same result.

Any ideas what can be wrong ? Thank you

An FTP connection is not a HTTP connection. Therefore i would say your FTP server needs to run a socket policy server on port 843 or on a different port and you have to call Security.PrefetchSocketPolicy manually. The crossdomain.xml file in the root folder of a webserver only grants access to that webserver. Any other ports / protocols aren’t affected by this file. Read the linked page carefully.