Send File Over FTP

Hey all, I'm attempting to configure a Send File Over FTP node but continue to receive an error relating to "The parameter is incorrect".  I have the newest version of the plugin (just installed), have verified the FTP connection is available utilizing FileZilla, and the Appian server and file share are located on the same network (no firewall issues).

The error received is:

[Appian Work Item - 99382 - ProcessExec00 : UnattendedJavaActivityRequest] ERROR com.appian.ps.plugins.sftpsmartservices.SendFileOverFTP - Error sending file
java.io.IOException: sun.net.ftp.FtpProtocolException: CWD in_bpm:21chris_test_doc.docx:550 The parameter is incorrect.

Caused by: sun.net.ftp.FtpProtocolException: CWD in_bpm:21chris_test_doc.docx:550 The parameter is incorrect.

I've reviewed the setup instructions, current configuration includes:

Server Hostname:  ="<SERVER_NAME>/in_bpm"

Server Port: 21

Remote Directory Path: chris_test_doc.docx

The credentials I'm supplying are my own, via Third-Party Credentials.  Any tips would be great!

Additionally, utilizing a service account, I'm receiving a "connection refused" error.  However when I copy/paste the username/password into FileZilla, this account can connect just fine.  I'm wondering if maybe the "@" in the password is causing an issue?  I have already changed the password once to remove other special characters (double quote, hash, etc).