Migration error, ARSZFLDG program step FTP does not write, error 550

[LWagner]

Has anyone encountered this error ?

I have superuser authority, created the target directories in HFS, and wrote the input files, but FTP will not write successfully in batch mode. 

I found I can do it in IKJEFT1A, so I could just edit the ARSFTP file appropriately.

I'd still like to know why the FTP fails.

Thanks In Advance