saeed shabani on "[Plugin: Easy Digital Downloads] zip file be damage after download"

I have the same issue as that say in this topic
When i use redirect mode all tings all right but in direct mode the zip file be damage after download.
How can use direct mode and haven’t this issue?

see this photo : http://i.imgur.com/pjrm4gs.jpg

https://wordpress.org/plugins/easy-digital-downloads/