Error when creating a new folder

I keep getting the following error when trying to create a new folder:
[10:46:15] RNFR /home/thatsbiz/thatsbiz/jsp/cu/New folder
[10:46:15] 550 RNFR command failed.

Are you running the latest version? https://www.smartftp.com/download/

Did you already contact support?
https://www.smartftp.com/support/kb/2653