SYMPTOM
While trying to work with a FTPS server on Windows server IIS, a FtpGet or FtpPut action ends without error but does nothing (no file is really transferred).
SOLUTION
Try to add '0' to the option 'FTP Protection Buffer Size' in the action:
Explanation: Some FTPS server requires that a value of '0' is always passed as a parameter for the buffer-size.