The problem isn’t the number of clients that you are connected to (you are already configured to connect to as many as 1,000 clients with 800 per torrent—note, with high-activity torrents, this might choke your Internet connection and/or router, and/or slow your system). The problem is the availability of the file.
There are two types of people in a torrent swarm, seeds and peers.
Seeds are people who have the complete file and peers are people who have part (or none) of a file.
When you want to download a file, you need to make sure that the entire file is available in the swarm. Seeds are good for this since they have the whole thing. However a swarm with no seeds can still have the whole file if the peers have different parts so that all parts available (eventually they will be converted to seeds as they get the parts that they’re missing). This is called the availability and is represented by a rational number; 1.0+ means the whole file is available and the higher the better.
In the case of your file (in the screenshot), there are 34 peers trying to download that file in the swarm, of which, you are connected to 12. You’ll note that there are zero seeds. Also note that the availability column indicates that only 99.7% of the file is available in the swarm, therefore that is the maximum you can attain.
Your options are limited:
- You can wait until a seed shows up (different times, different days are good ).
- You can ask someone to seed the file if you know somewhere to ask.
- You can make sure that DHT is enabled for that file if it is not.
- You can search for the file and add new trackers to it (try searching by its filename and/or its hash—in the General tab in the bottom pane).
- You can search for another torrent that has the file(s) and point the new torrent at your existing file(s), then force a re-check to avoid re-downloading the pieces you already have. Then, when finished, consider doing a re-check with the original torrent so that you can be a seed and help out the others who are stuck.
- If the torrent is a mult-file torrent, you could try searching for the individual files and getting torrents for those, then again, pointing those individual torrents at your existing files, re-checking, then continuing them. Again, consider seeding the original torrent to help the others (you don’t have to do it for too long since the others will quickly pick up the missing pieces and become seeds themselves).