FTP – WSAECONNRESET An existing connection was forcibly closed by the remote host.

One of the most common problems with FTP data transfers (including downloading directory listings) has to do with Passive vs. Active mode. Depending on your client/server/firewall situation, it’s probable that only one of the two modes will work (Active or Passive). Normally, if you choose the mode that doesn’t work, the data connection is blocked and you get a “WSAEWOULDBLOCK” error — meaning the TCP/IP data connection could not be established.

One Chilkat customer reported getting a WSAECONNRESET error when in Active mode. Switching to Passive mode fixed the problem.

In summary, if your FTP mode is Active (meaning the Passive property is set to false or 0) and you see the WSAECONNRESET error when trying to upload or download a file, or when trying to retrieve a directory listing, switch the mode to Passive and re-try.