This problem has been bugging for a few months. I'm using Chromium now but would like to switch back to Firefox if a solution could be found. I'm not holding my breath as I've tried almost all suggestions. The thing is, Firefox just does not tell me why it cancels my download. It surely knows why it does it, so why not just split it out to help people fix it. My question then is, how do I tell Firefox to tell me why it fails?