Automation FTP activity fails with "error FTP_1 The path is not of a legal form" (4308080)

Automation script is run but fails on the FTP action:

 "error FTP_1   The path is not of a legal form"

CAUSE 1: FTP action was set to DOWNLOAD instead of UPLOAD. Since the file didn't exist on the remote server, an error was displayed.

CAUSE 2: Option 'Transfer only if File exists' was checked, but the dialog box to detail filename was not populated.

RESOLUTION 1:

Ensure that the correct FTP direction is set.

RESOLUTION 2:

If 'Transfer ONLY if' is checked, then a value is expected in the dialog box.