Dowload Page doesnt work

So I installed the plugin, created a folder, uploaded all files, added my root folder path, edited my “thank you/download page” (added [download_page]), referer is empty.

Now when the download page is opened I get a broken download page saying “Sorry No File is specified to download.”
When adding ?f=”file” to my url the “download file window” appears so that seems to work.

Am I missing something?
I want the download page to appear when redirected from paypal after purchase and only want the links to be “scrambled” so the file location is not visibal – a nice “addon” would be expiring links….

http://wordpress.org/plugins/hide-real-download-path/