Changing which files are 'active' doesn't always take effect correctly until the client is restarted, which can lead to 'stalled at 0kb/s' downloads from all po

Changing which files are 'active' doesn't always take effect correctly until the client is restarted, which can lead to 'stalled at 0kb/s' downloads from all possible peers even if the torrent is stopped and then started without restarting the full app.