File not found when downloading

I create an upload page and I’m able to upload file in a specific directory, I creare the download page using the same directory and I can see the files that I have uploaded, but when I try to download I see a new page with the message “file not found” and also if I put the link in the browser the message is the same, but the strange thing is that if I try to download the file using the button with the Bulk Action Mode: Enabled all works!