I just wanted to share this after searching the archives and not seeing a
solution posted.

I got a call from a fellow consultant asking if there was a known problem
with FTP transferring empty files. After some research, I noticed the file
limit was set to zero (a Suprtool extract file).

Every time this file was PUT or GET through FTP, the result was the same:

The FILE SIZE parameter is invalid.  (FILE OPEN ERROR -380)
Data Transfer Request Failed.  (FTPERR 13)
The FILE SIZE parameter is invalid.  (FILE OPEN ERROR -380)

I noticed the word SIZE and issued a SIZE command on the file:

ftp> size pcmshe43
213 "pcmshe43": 3072 bytes

This didn't make sense, after all the file was empty. So, I did what any
MPEX user would do, I did an ALTFILE with the ;FLIMIT option and gave it
some head room.

This worked! The long term solution was to issue a SET SQUEEZE OFF in
SUPRTOOL.

I hope this saves someone the trouble anyway.