FTP RTT Monitor issues

I'm trying to create an FTP RTT monitor - just wanted it to test uploading and downloading in the root folder.

but the form won't let me proceed without putting something in the destination folder:

I tried just a "/" and I tried "/root" - but they both failed when the monitor ran with error:

Destination folder "/root" does not exits to upload.

Which kind of makes sense.
Any suggestions on how to get this monitor to work to upload just to the ftp root?