Hi, I have limited the upload to .zip files because I noticed that f.e. mp3 files will, sometimes, depending on the browser, get played directly inside the browser window wich makes it difficult to ensure that the file was actually downloaded by the user and not just cashed in the browser. It's there to reduce the risk for the user.
Modify your server configuration so it adds this header for all downloads and it will always popup the download file window for all files the same as it does for zip.
Content-Disposition: attachment