When running RA FTP job using FTPES protocol in Automation Engine V12.1.1 HF4 with Java 1.8,
the destination FTP server could receive the file, but FTP job report shows error message as below:
"550 The supplied message is incomplete. The signature was not verified."
The error: “550 The supplied message is incomplete. The signature was not verified.” is originating from the FTP server side.
Therefore the update has to be done on the MS IIS FTP server side and not on the client side.