I've successfully installed the plugin and everything seemed to be working fine up to the point where I wanted to download the file I've uploaded through the admin backend. That's where I got stuck with the error that file cannot be found or has been moved/renamed. I must be doing something wrong, but have no idea what after 3 hours of trial and error. Here's what I did so far (I've installed the plugin on a remote machine running WP 3.4.1, clean installation, no other plugins enabled):
First, I've checked the configuration -- the folder where the documents are getting uploaded to is writable (default WP folder where it stores media). Files are getting there alright, and I can see the hash+.ext . However, when I click on either the "View" or "Download" in the backend -- no luck. Just to be on the safe side, I've manually created another folder that I've pointed the plugin to, and ended up with the exact same problem. Files would get uploaded there, but I wouldn't be able to access them afterwards.
Then I've tried reconfiguring WP permalinks to a different format. That's where I've noticed that permalink that would get generated by the Plugin would call the original file name (e.g. http://www.site.com/documents/filename.doc) instead of the hash name (e.g. http://www.site.com/documents/asd932hdas9dj3d.doc) -- and of course fail.
I've gone through your discussion with another user and saw that you suggested he enabled FTP (I used the WP browser upload). I've tried that as well, but still no go -- I end up with the same error.
To put the problem simply: when I upload a file, it gets converted to a hash-name with the same extension as the original and get stored in the folder alright. But the permalink used to access it calls the original (non-hashed) filename and hence fails to locate the resource on the server.
What am I missing here?