eso no es un error del programa, sino de la web de donde estás descargando.
Dice que el torrent se ha borrado o que no está en el "pool" y que leas el FAQ de la web... copio del FAQ
What is this " Torrent not in pool yet" error I keep getting?
This means the tracker has not had the time to read the database yet. The tracker reads the database every 3 minutes or so, and then adds the new torrents to it's torrent pool. You need to wait for the torrent to be on the pool to be able to seed it. If you get this error, stop the transfer, wait 3 minutes (usually it takes less, but make it 3 to be sure), and then restart it.