I would like to share how i solved this problem.
Problem: when trying to download torrents the usual way, my preferred software "Deluge" could not find seeders or peers and it showed the error message "Error: Torrent not registred". This problem showed up just a week ago, or so.
Fix: I installed "utorrent", took me five minutes to install and set up the folders properly, and a new try with the same torrent worked immediately. I don't know what causes the issue, but this workes for me.
The advice came originally from some user by some comment in some post for some FIBA game on this website, can't find that user anymore, thank you though
Cheers!