No files/folders are displayed

After a successful login SFTP over SSH i can't see any files in the remote directory. Different settings of the directory listong options (List arguments) of the FTP Transfer tried, but no files displayed. The owner of the remote server tells me that all the access rights of my user are correct, and also that there are files in the specific directory. Can someone help with this please.
Software : SmartFtp v3.0.1022.18 Professional Edition

13:31:28] Reading directory "Y01A5344:/".
[13:31:28] 0 bytes transferred. (0 bytes/s) (15 ms)
[13:31:29] Resolving path "/Y01A5344:/OUTGOING".
[13:31:29] Path successfully resolved.

Thank for your reply.
I use now Prof. Edition 3.0 and i am wondering if i can use the same license key on version 4.0.

The maintenance (technical support and upgrades) of your license has expired. So the latest version is not covered. You can renew the maintenance at:
https://www.smartftp.com/purchase/renew.php