does not let download media

so I ma using the plugin
wp download manage , everything went smoothly
until I add the file to the post
https://www.mgdezigns.com/blog/freebievalentines-day-digital-scrapbook-kit/
when i click to download link it says
File does not exist.

however it is giving the correct filename with the file id inserted!
please help
is a chmod problem? where to fix and what..
Thanks