Confusingly, this thread says Firefox for Android AND Windows 10. But probably it is Windows where you have this issue. Do the links start with a magnet: protocol (i.e., instead of https:)? Assuming so, could you check the Windows control panel to see whether Bittorrent set up magnet: as a protocol it handles in the Windows Registry. To fire that up, you can type or paste ''protocol'' in the system search box and Windows should give you a link to the relevant part of the Default apps control panel. Firefox ''should'' be able to discover the protocol handler if it is in the Registry, but if it's already in there, hmm, some additional prodding might be needed.