Magnet links rely heavily on and UDP to find peers without a central tracker. If these are blocked or disabled, your download will sit at 0% forever. "Unable to download files for this magnet" - Deluge Forum

If the magnet link won't open automatically, the most reliable fix is to bypass the browser-to-app communication entirely.

: Right-click the magnet icon or link and select "Copy link address" or "Copy Link".

Dealing with the "unable to download files for this magnet" error in Deluge is a common frustration that usually stems from one of two things: a failure to communicate with the browser or a struggle to fetch "metadata" from the torrent network. 1. The Quick Manual Workaround

: Magnet links do not contain file information initially. Once added, the torrent status will change to "Downloading Metadata." It may take a minute for the files to appear. 2. Verify Your Network Settings

: In Deluge, go to File > Add Torrent > URL . Paste the link and click Add .