Display notification if torrent has no seeds or magnet link doesn't work

[quinncomendant]

The problem:

Some magnet links don't work, and the webtor UI doesn't show any errors. I'm not sure why this happens, but my guess it's when a torrent has no seeds.

Here's how to reproduce the issue:

1. Open https://webtor.io/#/
2. Paste in the following magnet link:

magnet:?xt=urn:btih:4E8E77A922EA08A19592EBAC6BD2A6340CEDFEC1&tr=http%3A%2F%2Fbt3.t-ru.org%2Fann%3Fmagnet&dn=(Electronic)%20Air%20-%20%D0%94%D0%B8%D1%81%D0%BA%D0%BE%D0%B3%D1%80%D0%B0%D1%84%D0%B8%D1%8F%20%2F%20Discography%20-%201997-2012%20%5BWEB%5D%2C%20AAC%20(tracks)%2C%20256%20kbps%20%5B%2BVideo%2C%20WEB-DL%2C%20480p%5D

3. Wait for the torrent to load. The progress bar at the top of the page moves about 30%, then stops after about 3 seconds, then the Paste magnet or infohash here field is erased. There is no notification why the request failed, which is very confusing to the the user (i.e., me).

What I expect to happen:

If the torrent has no seeds or is otherwise broken:

Display a notification to the user what went wrong.

If the torrent has seeds:

This works as expected. For valid magnet links with available files, Webtor works fine, and the list of files is displayed, and everything works as expected. Here's a magnet link that does work, so you can compare the experience with the other one:

magnet:?xt=urn:btih:B2B6961C11CA774B13CA19CCFEBE2B8A65E4485A&tr=http%3A%2F%2Fbt3.t-ru.org%2Fann%3Fmagnet&dn=(Downtempo%2FPop)%20Air%20%2F%20Darkel%20-%20Full%20Discography%20(11%20%2B%201%20CD)%20-%201998%20-%202012%2C%20FLAC%20(image%2B.cue)%2C%20lossless