Re: SFTP connection error - Server unexpectedly closed network connection
What does the server-side log say? Also have your network team check your firewalls.
Before posting, please read how to report bug or request support effectively.
Bug reports without an attached log file are usually useless.
. 2021-07-08 16:41:08.198 --------------------------------------------------------------------------
< 2021-07-08 16:41:08.198 Script: Searching for host...
. 2021-07-08 16:41:08.199 Looking up host "xxxx.com" for SSH connection
. 2021-07-08 16:41:08.213 Connecting to xxx.xxx.xxx.xxx port 22
< 2021-07-08 16:41:08.277 Script: Connecting to host...
. 2021-07-08 16:41:08.277 We claim version: SSH-2.0-WinSCP_release_5.19.1
. 2021-07-08 16:41:08.340 Remote side unexpectedly closed network connection
. 2021-07-08 16:41:08.340 Knocking FTP port.
. 2021-07-08 16:41:08.408 FTP port opened, will suggest using FTP protocol.
< 2021-07-08 16:41:08.409 Script: Server unexpectedly closed network connection.
< 2021-07-08 16:41:08.409 The server rejected SFTP connection, but it listens for FTP connections.
< 2021-07-08 16:41:08.409 Did you want to use FTP protocol instead of SFTP? Prefer using encryption.