The Error 425 is most often displayed when you have attempted to provide encoding.com a source FTP location that only supports Passive FTP mode.
If you are using a watch folder, check the box that says “Passive FTP Mode” in the ftp watch folder set up
If you are adding an individual file through the web interface or API you can append ?passive=yes to the end of your source or destination string:
ftp://user:pass@ftphost.tld/path/to/your/file.ext?passive=yes