If you test the Zip file before uploading it to an FTP server and no errors are reported, but after uploading the Zip file is damaged, the behavior is likely to be due to corruption of the Zip file during the file transfer. Please note that when transferring via FTP, the binary mode must be used; a text or ASCII transfer will always result in corruption of a Zip file.
(This information does not relate to either Send ToFTP Site (as Zip file) or the FTP option of the WinZip Job Wizard of WinZip Pro.)
If you have any questions about this information, please submit a Technical Support ticket.
Download results in a corrupt Zip file for some and not for others