Fix PHP Paper Download Bug -- 2

I run a research-paper journal site built in PHP and have hit a functionality snag: when visitors click the link to download a conference paper, absolutely nothing happens—no error, no partial file, just silence. Everything else on the site is fine; only this download function is misbehaving.

What I need is straightforward: locate the root cause, correct the code or server-side setting, and confirm that papers download cleanly again across common browsers. My preference is for a clean, well-commented fix so future updates remain painless, but speed matters too—I’d like this resolved as soon as possible.

Deliverables
• Repaired PHP/code or configuration enabling successful file download
• Brief note outlining the issue you found and the fix you applied
• Confirmation that downloads work on at least Chrome, Firefox, and Edge

If you’ve tackled similar PHP file-handling bugs, let’s get this sorted today.