The following errors may occur during a deployment via FTP:
Error communicating with your server: 426 Transfer aborted. Interrupted system call.
Error communicating with your server: 426 Failure reading network stream.
Which suggest the connection hasn't correctly completed or has been unexpectedly closed by the destination server. Primarily this may be caused by a loss of connection between DeployHQ and your server, and the server's FTP logs should be checked.
Please also ensure that our IP ranges are allowed through the server's firewall. It can help to switch between active and passive mode in your DeployHQ server setup.