I have been unable to get Ktorrent to start any new torrent for about a month now.
I have a desktop and a laptop running ktorrent and I even created a dual boot on my desktop to see if it was my old installs but the new install on my alternate boot (Note: They are ALL Kubuntu 16.04).
I have set my browser (Firefox) to let Ktorrent handle '.torrent' files but when I left click on the magnet link, nothing happens. When I right click and select 'copy link location', then in Ktorrent I select 'file/open url', the dialogue box opens with the link there, but when I click on 'OK', nothing happens.

I have also just tried Chrome and I get the same result - Nothing.

try installing another torrent client. deluge or qbittorrent would be my suggestions. i have never liked the torrent clients that come with distros, rather that be ktorrent, transmission, ect........ by doing this if you still have the same issue at least you know most likely it's not ktorrent having the problem and most likely your distro that is.

I installed qBittorrent and everything is working as expected.